UNITED STATES SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

Form 10-K

Commission File Number 1-13232

Apartment Investment and Management Company

(Exact name of registrant as specified in its charter)

Registrant’s telephone number, Including Area Code: (303) 757-8101

Securities Registered Pursuant to Section 12(b) of the Act:

Securities Registered Pursuant to Section 12(g) of the Act: none

     Indicate by check mark if the registrant is a well-known seasoned issuer, as defined by Rule 405 of the Securities Act.    Yes þ         No o

     Indicate by check mark if the registrant is not required to file reports pursuant to Section 13 or Section 15(d) of the Act.    Yes o         No þ

     Indicate by check mark whether the registrant (1) has filed all reports required to be filed by Section 13 or 15(d) of the Securities Exchange Act of 1934 during the preceding 12 months (or for such shorter period that the registrant was required to file such reports), and (2) has been subject to such filing requirements for the past 90 days.    Yes þ         No o

     Indicate by check mark if disclosure of delinquent filers pursuant to Item 405 of Regulation S-K is not contained herein, and will not be contained, to the best of registrant’s knowledge, in definitive proxy or information statements incorporated by reference in Part III of this Form 10-K or any amendment to this Form 10-K.    o

     Indicate by check mark whether the registrant is a large accelerated filer, an accelerated filer, or a non-accelerated filer. See definition of “accelerated filer and large accelerated filer” in Rule 12b-2 of the Exchange Act. (Check one):

Large accelerated filer þ             Accelerated o             Non-accelerated filer o

     Indicate by check mark whether the registrant is a shell company (as defined in Rule 12b-2 of the Act).    Yes o         No þ

     The aggregate market value of the voting and non-voting common stock held by non-affiliates of the registrant, was approximately $3.9 billion as of June 30, 2005. As of February 28, 2006, there were 96,566,698 shares of Class A Common Stock outstanding.

DOCUMENTS INCORPORATED BY REFERENCE

     Portions of the registrant’s definitive proxy statement to be issued in conjunction with the registrant’s annual meeting of stockholders to be held May 10, 2006 are incorporated by reference into Part III of this Annual Report.

APARTMENT INVESTMENT AND MANAGEMENT COMPANY

TABLE OF CONTENTS

ANNUAL REPORT ON FORM 10-K

For the Fiscal Year Ended December 31, 2005

FORWARD-LOOKING STATEMENTS

      The Private Securities Litigation Reform Act of 1995 provides a “safe harbor” for forward-looking statements in certain circumstances. Certain information included in this Annual Report on Form 10-K (“Annual Report”) contains or may contain information that is forward-looking, including, without limitation, statements regarding the effect of acquisitions, our future financial performance and the effect of government regulations. Actual results may differ materially from those described in the forward-looking statements and will be affected by a variety of risks and factors that are beyond our control including, without limitation: natural disasters such as hurricanes, national and local economic conditions; the general level of interest rates; energy costs; the terms of governmental regulations that affect us and interpretations of those regulations; the competitive environment in which we operate; financing risks, including the risk that our cash flows from operations may be insufficient to meet required payments of principal and interest; real estate risks, including fluctuations in real estate values and the general economic climate in local markets and competition for tenants in such markets; insurance risks; acquisition and development risks, including failure of such acquisitions and development projects to perform in accordance with projections; the timing of acquisitions and dispositions; litigation, including costs associated with prosecuting or defending claims and any adverse outcomes; and possible environmental liabilities, including costs, fines or penalties that may be incurred due to necessary remediation of contamination of properties presently owned or previously owned by us. In addition, our current and continuing qualification as a real estate investment trust involves the application of highly technical and complex provisions of the Internal Revenue Code and depends on our ability to meet the various requirements imposed by the Internal Revenue Code, through actual operating results, distribution levels and diversity of stock ownership. Readers should carefully review our financial statements and the notes thereto, as well as the section entitled “Risk Factors” described in Item 1A of this Annual Report and the other documents we file from time to time with the Securities and Exchange Commission.

PART I

Item 1.     Business

The Company

      Apartment Investment and Management Company, or Aimco, is a Maryland corporation incorporated on January 10, 1994. We are a self-administered and self-managed real estate investment trust, or REIT, engaged in the acquisition, ownership, management and redevelopment of apartment properties. As of December 31, 2005, we owned or managed a real estate portfolio of 1,370 apartment properties containing 240,484 apartment units located in 47 states, the District of Columbia and Puerto Rico. Based on apartment unit data compiled by the National Multi Housing Council, as of December 31, 2005 we were the largest REIT owner and operator of apartment properties in the United States. Our portfolio includes garden style, mid-rise and high-rise properties.

      We own an equity interest in, and consolidate the majority of, the properties in our owned real estate portfolio. These properties represent the consolidated real estate holdings in our financial statements, which we refer to as consolidated properties. In addition, we have an equity interest in, but do not consolidate for financial statement purposes, certain properties that are accounted for under the equity method. These properties represent our investment in unconsolidated real estate partnerships in our financial statements, which we refer to as unconsolidated properties. Additionally, we manage (both property and asset) but do not own an equity interest in other properties, although in certain cases we may indirectly own generally less than one percent of the

operations of such properties through a partnership syndication or other fund. Our equity holdings and managed properties are as follows as of December 31, 2005:

      Through our wholly-owned subsidiaries, AIMCO-GP, Inc. and AIMCO-LP, Inc., we own a majority of the ownership interests in AIMCO Properties, L.P., which we refer to as the Aimco Operating Partnership. As of December 31, 2005, we held approximately a 90% interest in the common partnership units and equivalents of the Aimco Operating Partnership. We conduct substantially all of our business and own substantially all of our assets through the Aimco Operating Partnership. Interests in the Aimco Operating Partnership that are held by limited partners other than Aimco are referred to as “OP Units.” OP Units include common OP Units, partnership preferred units, or preferred OP Units, and high performance partnership units, or High Performance Units. Generally after a holding period of twelve months, holders of common OP Units may redeem such units for cash or, at the Aimco Operating Partnership’s option, Aimco Class A Common Stock, which we refer to as Common Stock. At December 31, 2005, 95,732,200 shares of our Common Stock were outstanding and the Aimco Operating Partnership had 10,339,262 common OP Units and equivalents outstanding for a combined total of 106,071,462 shares of Common Stock and OP Units outstanding (excluding preferred OP Units).

      Since our initial public offering in July 1994, we have completed numerous transactions, expanding our portfolio of owned or managed properties from 132 properties with 29,343 apartment units to 1,370 properties with 240,484 apartment units as of December 31, 2005. These transactions have included purchases of properties and interests in entities that own or manage properties, as well as corporate mergers.

      Except as the context otherwise requires, “we,” “our,” “us” and the “Company” refer to Aimco, the Aimco Operating Partnership and their consolidated entities, collectively. As used herein, and except where the context otherwise requires, “partnership” refers to a limited partnership or a limited liability company and “partner” refers to a limited partner in a limited partnership or a member in a limited liability company.

Available Information

      Our Annual Report on Form 10-K, our Quarterly Reports on Form 10-Q, our Current Reports on Form 8-K and any amendments to any of those reports that we file with the Securities and Exchange Commission are available free of charge as soon as reasonably practicable through our website at www.aimco.com. The information contained on our website is not incorporated into this Annual Report. Our Common Stock is listed on the New York Stock Exchange under the symbol “AIV.” In 2005, our chief executive officer submitted his annual corporate governance listing standards certification to the New York Stock Exchange, which certification was unqualified.

Financial Information About Industry Segments

      We operate in two reportable segments: real estate (owning and operating apartments) and investment management business (providing property management and other services relating to the apartment business to third parties and affiliates). For further information on these segments, see Note 17 of the consolidated financial statements in Item 8, and Management’s Discussion and Analysis in Item 7.

Business Overview

      Our principal objective is to increase long-term stockholder value, which we believe results from increasing asset values, increasing operating cash flows and long-term, predictable Funds From Operations, or FFO (as

defined by the National Association of Real Estate Investment Trusts), per share of Common Stock, less capital spending for replacements. For a description of the meaning of FFO and its use and limitations as an operating measure, see the discussion titled “Funds From Operations” in Item 7.

      We strive to meet our objectives by focusing on property operations, generation of fees, portfolio management, reinvestment in properties, increasing land values through entitlements, managing our cost of capital by using leverage that is largely long-term, non-recourse and property specific, and managing our general and administrative costs through increasing productivity.

      We divide property operations into two business components: conventional and affordable. Our conventional operations, which are market-rate apartments with rents paid by the resident, include 526 properties with 151,613 units and also include our university communities portfolio (15 properties with 4,443 units). Aimco Capital conducts our affordable operations of 357 properties with 42,204 units, which typically are apartments with rents frequently subsidized or paid by a government agency.

      Our property operations are characterized by diversification of product, location and price point. We operate a broad range of property types, from suburban garden-style to urban high-rise properties in 47 states, the District of Columbia and Puerto Rico at a broad range of average monthly rental rates, with most between $500 and $1,100 per month, and reaching as high as $6,400 per month at some of our premier properties. This geographic diversification insulates us, to some degree, from inevitable downturns in any one market.

      Our conventional operations at the beginning of 2006 were organized into four divisions, each of which is supervised by a Division Vice President, or DVP, and were further sub-divided into 17 regional operating centers, or ROCs. As changes in our portfolio occur, we reevaluate this structure. A Regional Vice President, or RVP, supervises each ROC. The ROCs are generally smaller business units with specialized operational, financial and human resource leadership. We seek to improve the operating results from our property operations by, among other methods, combining centralized financial control and uniform operating procedures with localized property management decision-making and market knowledge. To manage our nationwide portfolio more efficiently and to increase the benefits from our local management expertise, we have given direct responsibility for operations to the RVP with oversight from extensive regular reviews with senior management. To enable the RVPs to focus on sales and service, as well as improve financial control and budgeting, we have dedicated a regional financial officer to support each RVP. In addition, our construction services group handles all work on site beyond routine maintenance, thus reducing the need for RVPs to spend time on oversight of construction projects. We continue to improve our corporate-level oversight of conventional property operations by developing better systems, standardizing business goals, operational measurements and internal reporting, and enhancing financial controls over field operations. Our objectives are to focus on the areas discussed below:

      We are among the largest owners and operators of affordable properties in the United States. Aimco Capital was organized to focus on our affordable housing properties, the operations of which are most often subsidized or financed by the United States Department of Housing and Urban Development, or HUD, state housing agencies or tax credit financing, and is led by a management team dedicated to this sector. Aimco Capital operates our affordable properties through three ROCs. Affordable properties tend to have stable rents and occupancy due to government subsidies and thus are much less affected by market circumstances.

      Aimco Capital also generates activity fees from transactions related to affordable holdings (including tax credit redevelopments, syndications, dispositions and refinancings), and asset management income from the financial management of our owned and operated affordable portfolio as well as two other large portfolios for which we provide asset management services only. We believe that Aimco Capital is well positioned as it has the national structure, knowledge and pipeline to grow as a more autonomous operation with dedicated capital.

      We view our conventional property portfolio in terms of “core” and “non-core” properties. Core properties are those properties that are located in markets where population and employment growth are expected to exceed national trends and where we believe there is potential for long-term growth at higher rates of return. During 2005, we made a decision to concentrate our core portfolio in markets located predominantly in coastal states as well as the Rocky Mountain region and Chicago. This reduced the number of markets in which we intend to remain from 38 to 27. We plan to exit certain Texas and Midwest markets where the average four-year growth rate is projected below average of the remainder of the core portfolio. At December 31, 2005, we had 272 conventional core properties, which generally we intend to hold and improve over the long-term. Within our core portfolio, the largest single market (Washington, D.C.) contributed approximately 10%, and the five largest markets (Washington, D.C., greater Los Angeles, New England, Philadelphia and Miami-Fort Lauderdale) together contributed approximately 38%, to income before depreciation and interest expense, or net operating income. At December 31, 2005, we had 254 conventional non-core properties, which we generally intend to hold for investment for the intermediate term. Non-core properties are those properties located within the 32 markets we intend to exit or in less favored locations within the 27 markets that comprise our core portfolio. We exited nine markets in 2005. During 2006, we expect to exit an additional five markets and over the next several years we expect to exit the remaining markets in which we hold our non-core properties.

      Portfolio management includes expanding our core portfolio through acquisitions of properties located in markets where our core portfolio is concentrated. We specifically seek investments in a variety of asset qualities and types at a purchase price below replacement cost. Currently, we acquire properties and property interests primarily in three ways:

      In 2005, we completed direct acquisitions of six conventional core properties, containing approximately 1,006 residential units and six retail spaces for an aggregate purchase price of approximately $284 million (including transaction costs) and acquired additional interests in 84 partnerships for approximately $56 million (including transaction costs). These properties were located in New York City, New Jersey and Los Angeles.

      Portfolio management also includes dispositions of properties located within markets we intend to exit, properties in less favored locations within the 27 markets that comprise our core portfolio or properties that do not meet our long-term investment criteria. Additionally, from time to time, we may dispose of certain core properties that are consistent with our long-term investment strategy but offer attractive returns, such as in sales to buyers who intend to convert the properties to condominiums. The sales of core and non-core properties partially fund our acquisitions and capital improvements on our existing properties. In 2005, we sold 71 non-core properties generating net cash proceeds to us, after repayment of existing debt, payment of transaction costs and distributions to limited partners, of $262 million.

      The portfolio management strategy for Aimco Capital is similar to that of our Conventional portfolio. Aimco Capital seeks to dispose of properties that are inconsistent with our long-term investment strategy and Aimco Capital’s operations. During 2005, we sold 47 non-core properties from within the Aimco Capital portfolio, generating net cash proceeds to us, after repayment of existing debt, payment of transaction costs and distributions to limited partners, of $70 million. At December 31, 2005 within the Aimco Capital portfolio, we had 357 properties, a majority of which are non-core properties that we generally intend to hold for investment for the intermediate term. During 2006, we intend to sell approximately the same number of Aimco Capital properties as we sold in 2005.

      We have the opportunity to improve land values by seeking new entitlements for many properties. Entitlements provide us the opportunity to enhance the value of our existing portfolio by obtaining local governmental approvals to increase density and add dwelling or residential units to a site. Also we seek to add incremental value through redevelopment of existing units and excess land sales. We currently have 50 entitlement projects under way or under review. These properties are typically well located and in many cases were built 30 or more years ago. During 2005, we received final approval on the conceptual site plan for Springhill Lake in Greenbelt, Maryland, which includes doubling the density of the property from 2,899 units to 5,800 units.

      We believe that the physical condition and amenities of our apartment properties are important factors in our ability to maintain and increase rental rates. In 2005, we spent $89.7 million, or $597 per owned apartment unit, for Capital Replacements, which represent the share of expenditures that are deemed to replace the consumed portion of acquired capital assets. Additionally, we spent $112.0 million for Capital Improvements, which are non-redevelopment capital expenditures that are made to enhance the value, profitability or useful life of an asset from its original purchase condition.

      In addition to maintenance and improvements of our properties, we focus on the redevelopment of certain properties each year. We believe redevelopment of certain properties in superior locations provides advantages over ground-up development, enabling us to generate rents comparable to new properties with relatively lower financial risk, in less time and with reduced delays associated with governmental permits and authorizations. We undertake two types of redevelopment projects: major projects, where a substantial number or all available units are vacated for significant renovations to the property; and moderate projects, where there is significant renovation, such as exteriors, common areas or unit improvements, typically done upon lease expirations without the need to vacate units on any wholesale or substantial basis. We have a specialized Redevelopment and Construction Services Group, which includes engineers, architects and construction managers, to oversee these projects. As of December 31, 2005, we had 59 projects at various stages of redevelopment. Of the 59 projects, 37 are conventional properties (two major projects and 35 moderate projects) and 22 are affordable properties. During 2005, redevelopment expenditures totaled $203.5 million, of which our share totaled $140.3 million, and we completed our two major projects as well as interior upgrades or new construction on 2,188 conventional units, of which 1,687 were leased at year-end for increased rental rates. Total redevelopment expenditures for our 35 active conventional moderate projects will be approximately $228.9 million, of which approximately $108.4 million remains to be spent. Total redevelopment expenditures for our 22 affordable redevelopments will be approximately $142.0 million, of which approximately $52.5 million remains to be spent, most of which will be funded by third-party tax credit equity and tax-exempt debt. In 2006, we plan to invest between $150 and $200 million in conventional redevelopment projects that will impact approximately 70 properties with nearly 30,000 units. Additionally, in 2006 redevelopment expenditures on affordable properties will be approximately $80 million, predominantly funded by third-party tax credit equity, impacting 20 to 25 properties with more than 3,000 units.

      We are focused on minimizing our cost of capital. We have a deliberate policy of using non-recourse property debt. The lower risk inherent in non-recourse property debt permits us to operate with higher debt leverage and a lower weighted average cost of capital. During 2005, we closed loans totaling $971.5 million at an average interest rate of 5.06%, which included the refinancing of loans totaling $415.2 million with prior interest rates averaging 7.33%. In 2006, we intend to further reduce our cost of capital through the redemption of $286.8 million of preferred securities at a weighted average cost of 9.76%.

      Over the past several years, we have had growth in our general and administrative spending as a result of the building of our infrastructure in certain areas in which we had needs, including, operational systems, information technology and other automation, human resources, and expanded accounting, legal, and financial planning and analysis functions. We are focused on containing this spending going forward through enhanced productivity, process improvements and staff reductions.

Competition

      In attracting and retaining residents to occupy our properties we compete with numerous other housing alternatives. Our properties compete directly with other rental apartments, as well as with condominiums and single-family homes that are available for rent or purchase in the markets in which our properties are located. Principal factors of competition include rent or price charged, attractiveness of the location and property and quality and breadth of services. The number of competitive properties in a particular area has a material effect on our ability to lease apartment units at our properties and on the rents we charge. Additionally, we compete with other real estate investors, including other apartment REITs, pension and investment funds, partnerships and investment companies in acquiring, redeveloping and managing apartment properties. This competition affects our ability to acquire properties we want to add to our portfolio and the price that we pay in such acquisitions.

Taxation

      We have elected to be taxed as a REIT under the Internal Revenue Code of 1986, as amended, which we refer to as the Code, commencing with our taxable year ended December 31, 1994, and intend to continue to operate in such a manner. Our current and continuing qualification as a REIT depends on our ability to meet the various requirements imposed by the Code, which are related to organizational structure, distribution levels, diversity of stock ownership and certain restrictions with regard to owned assets and categories of income. If we qualify for taxation as a REIT, we will generally not be subject to United States Federal corporate income tax on our taxable income that is currently distributed to stockholders. This treatment substantially eliminates the “double taxation” (at the corporate and stockholder levels) that generally results from investment in a corporation.

      Even if we qualify as a REIT, we may be subject to United States Federal income and excise taxes in various situations, such as on our undistributed income. We also will be required to pay a 100% tax on any net income on non-arm’s length transactions between us and a TRS (described below) and on any net income from sales of property that was property held for sale to customers in the ordinary course. We and our stockholders may be subject to state or local taxation in various state or local jurisdictions, including those in which we transact business or our stockholders reside. Any taxes imposed on us would reduce our operating cash flow and net income. The state and local tax laws may not conform to the United States Federal income tax treatment.

      Certain of our operations (property management, asset management, risk, etc.) are conducted through taxable REIT subsidiaries, each of which we refer to as a TRS. A TRS is a C-corporation that has not elected REIT status and as such is subject to United States Federal corporate income tax. We use the TRS format to facilitate our ability to offer certain services and activities to our residents, which services and activities are not generally considered as qualifying REIT activities.

Regulation

      Apartment properties are subject to various laws, ordinances and regulations, including regulations relating to recreational facilities such as swimming pools, activity centers and other common areas. Changes in laws increasing the potential liability for environmental conditions existing on properties or increasing the restrictions on discharges or other conditions, as well as changes in laws affecting development, construction and safety requirements, may result in significant unanticipated expenditures, which would adversely affect our net income and cash flows from operating activities. In addition, future enactment of rent control or rent stabilization laws or other laws regulating multifamily housing may reduce rental revenue or increase operating costs in particular markets.

      Various Federal, state and local laws subject property owners or operators to liability for management, and the costs of removal or remediation, of certain hazardous substances present on a property. Such laws often impose liability without regard to whether the owner or operator knew of, or was responsible for, the release or presence of the hazardous substances. The presence of, or the failure to manage or remedy properly, hazardous substances may adversely affect occupancy at affected apartment communities and the ability to sell or finance affected properties. In addition to the costs associated with investigation and remediation actions brought by government agencies, and potential fines or penalties imposed by such agencies in connection therewith, the presence of hazardous substances on a property could result in claims by private plaintiffs for personal injury, disease, disability or other infirmities. Various laws also impose liability for the cost of removal, remediation or disposal of hazardous substances through a licensed disposal or treatment facility. Anyone who arranges for the disposal or treatment of hazardous substances is potentially liable under such laws. These laws often impose liability whether or not the person arranging for the disposal ever owned or operated the disposal facility. In connection with the ownership, operation and management of properties, we could potentially be liable for environmental liabilities or costs associated with our properties or properties we acquire or manage in the future.

      We have been named as a defendant in lawsuits that have alleged personal injury and property damage as a result of the presence of mold. In addition, we are aware of lawsuits against owners and managers of multifamily properties asserting claims of personal injury and property damage caused by the presence of mold, some of which have resulted in substantial monetary judgments or settlements. We have only limited insurance coverage for property damage loss claims arising from the presence of mold and for personal injury claims related to mold exposure. We have implemented policies, procedures, third-party audits and training, and include a detailed moisture intrusion and mold assessment during acquisition due diligence. We believe these measures will prevent or eliminate mold exposure from our properties and will minimize the effects that mold may have on our residents. To date, we have not incurred any material costs or liabilities relating to claims of mold exposure or to abate mold conditions. Because the law regarding mold is unsettled and subject to change we can make no assurance that liabilities resulting from the presence of or exposure to mold will not have a material adverse effect on our consolidated financial condition or results of operations.

Insurance

      Our primary lines of insurance coverage are property, general liability, and workers’ compensation. We believe that our insurance coverages adequately insure our properties against the risk of loss attributable to fire, earthquake, hurricane, tornado, flood and other perils and adequately insure us against other risks. Our coverage includes deductibles, retentions and limits that are customary in the industry. We have established loss prevention, loss mitigation, claim handling, litigation management and loss reserving procedures to manage our exposure.

Employees

      We currently have approximately 6,400 employees, of which approximately 5,200 are at the property level, performing various on-site functions, with the balance managing corporate and regional operations, including investment and debt transactions, legal, financial reporting, accounting, information systems, human resources and other support functions. Unions represent approximately 200 of our employees. We have never experienced a work stoppage and believe we maintain satisfactory relations with our employees.

Item 1A.     Risk Factors

      The risk factors noted in this section and other factors noted throughout this Annual Report, describe certain risks and uncertainties that could cause our actual results to differ materially from those contained in any forward-looking statement.

      Our ability to make payments to our investors depends on our ability to generate net operating income in excess of required debt payments and capital expenditure requirements. Net operating income may be adversely affected by events or conditions beyond our control, including:

      The selective acquisition, redevelopment and expansion of properties are components of our strategy. However, we may not be able to complete transactions successfully in the future. Although we seek to acquire, operate, redevelop and expand properties only when such activities increase our net income on a per share basis, such transactions may fail to perform in accordance with our expectations. When we redevelop or expand properties, we are subject to the risks that:

      Our strategy is generally to incur debt to increase the return on our equity while maintaining acceptable interest coverage ratios. For the year ended December 31, 2005, we had a ratio of free cash flow (net operating income less spending for capital replacements) to combined interest expense and preferred stock dividends of 1.4:1. Our organizational documents do not limit the amount of debt that we may incur, and we have significant amounts of debt outstanding. Payments of principal and interest may leave us with insufficient cash resources to operate our properties or pay distributions required to be paid in order to maintain our qualification as a REIT. We are also subject to the risk that our cash flow from operations will be insufficient to make required payments of principal and interest, and the risk that existing indebtedness may not be refinanced or that the terms of any refinancing will not be as favorable as the terms of existing indebtedness. If we fail to make required payments of principal and interest on secured debt, our lenders could foreclose on the properties securing such debt, which would result in loss of income and asset value to us. As of December 31, 2005, substantially all of the properties that we owned or controlled were encumbered by debt.

      As of December 31, 2005, we had approximately $2,010.5 million of variable-rate indebtedness outstanding. Of the total debt subject to variable interest rates, floating rate tax-exempt bond financing was $726.1 million. Floating rate tax-exempt bond financing is benchmarked against the BMA Index, which since 1981 has averaged 68.0% of 30-day LIBOR. If this relationship continues, an increase in the 30-day LIBOR, of 1% (0.68% in tax-exempt interest rates) would result in our income before minority interests and cash flows being reduced by $17.8 million on an annual basis. This would be offset by variable rate interest income earned on certain assets, including cash and cash equivalents and notes receivable, as well as interest that is capitalized on a portion of this variable rate debt incurred in connection with our redevelopment activities. Considering these offsets, the same increase in the 30-day LIBOR would result in our income before minority interests being reduced by $8.9 million on an annual basis.

      Some of our debt and other securities contain covenants that restrict our ability to make distributions or other payments to our investors unless certain financial tests or other criteria are satisfied. Our credit facility provides, among other things, that we may make distributions to our investors during any four consecutive fiscal quarters in an aggregate amount that does not exceed the greater of 95% of our Funds From Operations for such period or such amount as may be necessary to maintain our REIT status. Our outstanding classes of preferred stock

prohibit the payment of dividends on our Common Stock if we fail to pay the dividends to which the holders of the preferred stock are entitled.

      All of our properties are owned, and all of our operations are conducted, by the Aimco Operating Partnership and our other subsidiaries. As a result, we depend on distributions and other payments from our subsidiaries in order to satisfy our financial obligations and make payments to our investors. The ability of our subsidiaries to make such distributions and other payments depends on their earnings and may be subject to statutory or contractual limitations. As an equity investor in our subsidiaries, our right to receive assets upon their liquidation or reorganization will be effectively subordinated to the claims of their creditors. To the extent that we are recognized as a creditor of such subsidiaries, our claims may still be subordinate to any security interest in or other lien on their assets and to any of their debt or other obligations that are senior to our claims.

      We have engaged in, and intend to continue to engage in, the selective acquisition of interests in partnerships that own apartment properties. In some cases, we have acquired the general partner of a partnership and then made an offer to acquire the limited partners’ interests in the partnership. In these transactions, we may be subject to litigation based on claims that we, as the general partner, have breached our fiduciary duty to our limited partners or that the transaction violates the relevant partnership agreement or state law. Although we intend to comply with our fiduciary obligations and the relevant partnership agreements, we may incur additional costs in connection with the defense or settlement of this type of litigation. In some cases, this type of litigation may adversely affect our desire to proceed with, or our ability to complete, a particular transaction. Any litigation of this type could also have a material adverse effect on our financial condition or results of operations.

      The insurance market is characterized by volatility with respect to premiums, deductibles and coverage. Although we make use of many alternative methods of risk financing that enable us to insulate ourselves to some degree from variations in coverage and cost, sustained deterioration in insurance marketplace conditions may have a negative effect on our operating results.

      From time to time, the Federal Bureau of Investigation, or FBI, and the United States Department of Homeland Security issue alerts regarding potential terrorist threats involving apartment buildings. Threats of future terrorist attacks, such as those announced by the FBI and the Department of Homeland Security, could have a negative effect on rent and occupancy levels at our properties. The effect that future terrorist activities or threats of such activities could have on our business is uncertain and unpredictable. If we incur a loss at a property as a result of an act of terrorism, we could lose all or a portion of the capital we have invested in the property, as well as the future revenue from the property.

      Our success depends upon the retention of our senior management, including Terry Considine, our chief executive officer and president. There are no assurances that we would be able to find qualified replacements for the individuals who make up our senior management if their services were no longer available. The loss of services of one or more members of our senior management team could have a material adverse effect on our business, financial condition and results of operations. We do not currently maintain key-man life insurance for any of our employees. The loss of any member of senior management could adversely affect our ability to pursue effectively our business strategy.

      We own an equity interest in certain affordable properties and manage for third parties and affiliates other properties that benefit from governmental programs intended to provide housing to people with low or moderate incomes. These programs, which are usually administered by HUD or state housing finance agencies, typically provide mortgage insurance, favorable financing terms or rental assistance payments to the property owners. As a condition of the receipt of assistance under these programs, the properties must comply with various requirements, which typically limit rents to pre-approved amounts. If permitted rents on a property are insufficient to cover costs, a sale of the property may become necessary, which could result in a loss of management fee revenue. We usually need to obtain the approval of HUD in order to manage, or acquire a significant interest in, a HUD-assisted property. We may not always receive such approval.

      Under the Americans with Disabilities Act of 1990, or ADA, all places intended to be used by the public are required to meet certain Federal requirements related to access and use by disabled persons. Likewise, the Fair Housing Amendments Act of 1988, or FHAA, requires apartment properties first occupied after March 13, 1990 to be accessible to the handicapped. These and other Federal, state and local laws may require modifications to our properties, or restrict renovations of the properties. Noncompliance with these laws could result in the imposition of fines or an award of damages to private litigants and also could result in an order to correct any non-complying feature, which could result in substantial capital expenditures. Although we believe that our properties are substantially in compliance with present requirements, we may incur unanticipated expenses to comply with the ADA and the FHAA.

      If we fail to qualify as a REIT, we will not be allowed a deduction for dividends paid to our stockholders in computing our taxable income, and we will be subject to Federal income tax at regular corporate rates, including any applicable alternative minimum tax. This would substantially reduce our funds available for payment to our investors. Unless entitled to relief under certain provisions of the Code, we also would be disqualified from taxation as a REIT for the four taxable years following the year during which we ceased to qualify as a REIT. In addition, our failure to qualify as a REIT would trigger the following consequences:

      We believe that we operate, and have always operated, in a manner that enables us to meet the requirements for qualification as a REIT for Federal income tax purposes. Our continued qualification as a REIT will depend on our satisfaction of certain asset, income, investment, organizational, distribution, stockholder ownership and other requirements on a continuing basis. Our ability to satisfy the asset tests depends upon our analysis of the fair market values of our assets, some of which are not susceptible to a precise determination, and for which we will not obtain independent appraisals. Our compliance with the REIT income and quarterly asset requirements also depends upon our ability to manage successfully the composition of our income and assets on an ongoing basis. Moreover, the proper classification of an instrument as debt or equity for Federal income tax purposes may be uncertain in some circumstances, which could affect the application of the REIT qualification requirements. Accordingly, there can be no assurance that the Internal Revenue Service, or the IRS, will not contend that our interests in subsidiaries or other issuers constitutes a violation of the REIT requirements. Moreover, future economic, market, legal, tax or other considerations may cause us to fail to qualify as a REIT, or our Board of Directors may determine to revoke our REIT status.

      As a REIT, we are subject to annual distribution requirements, which limit the amount of cash we retain for other business purposes, including amounts to fund our growth. We generally must distribute annually at least

90% of our net REIT taxable income, excluding any net capital gain, in order for our distributed earnings not to be subject to corporate income tax. We intend to make distributions to our stockholders to comply with the requirements of the Code. However, differences in timing between the recognition of taxable income and the actual receipt of cash could require us to sell assets or borrow funds on a short-term or long-term basis to meet the 90% distribution requirement of the Code.

      Our charter limits ownership of our Common Stock by any single stockholder (applying certain “beneficial ownership” rules under Federal securities laws) to 8.7% of our outstanding shares of Common Stock, or 15% in the case of certain pension trusts, registered investment companies and Mr. Considine. Our charter also limits ownership of our Common Stock and preferred stock by any single stockholder to 8.7% of the value of the outstanding Common Stock and preferred stock, or 15% in the case of certain pension trusts, registered investment companies and Mr. Considine. The charter also prohibits anyone from buying shares of our capital stock if the purchase would result in us losing our REIT status. This could happen if a transaction results in fewer than 100 persons owning all of our shares of capital stock or results in five or fewer persons (applying certain attribution rules of the Code) owning 50% or more of the value of all of our shares of capital stock. If anyone acquires shares in excess of the ownership limit or in violation of the ownership requirements of the Code for REITs:

      We may purchase the shares of capital stock held in trust at a price equal to the lesser of the price paid by the transferee of the shares or the then current market price. If the trust transfers any of the shares of capital stock, the affected person will receive the lesser of the price paid for the shares or the then current market price. An individual who acquires shares of capital stock that violate the above rules bears the risk that the individual:

      The 8.7% ownership limit discussed above may have the effect of precluding acquisition of control of us by a third party without the consent of our Board of Directors. Our charter authorizes our Board of Directors to issue up to 510,587,500 shares of capital stock. As of December 31, 2005, 426,157,976 shares were classified as Common Stock, of which 95,732,200 were outstanding, and 84,429,524 shares were classified as preferred stock, of which 38,324,762 were outstanding. Under our charter, our Board of Directors has the authority to classify and reclassify any of our unissued shares of capital stock into shares of capital stock with such preferences, rights, powers and restrictions as our Board of Directors may determine. The authorization and issuance of a new class

of capital stock could have the effect of delaying or preventing someone from taking control of us, even if a change in control were in our stockholders’ best interests.

      As a Maryland corporation, we are subject to various Maryland laws that may have the effect of discouraging offers to acquire us and increasing the difficulty of consummating any such offers, even if an acquisition would be in our stockholders’ best interests. The Maryland General Corporation Law restricts mergers and other business combination transactions between us and any person who acquires beneficial ownership of shares of our stock representing 10% or more of the voting power without our Board of Directors’ prior approval. Any such business combination transaction could not be completed until five years after the person acquired such voting power, and generally only with the approval of stockholders representing 80% of all votes entitled to be cast and 66²/3% of the votes entitled to be cast, excluding the interested stockholder, or upon payment of a fair price. Maryland law also provides generally that a person who acquires shares of our capital stock that represent 10% or more of the voting power in electing directors will have no voting rights unless approved by a vote of two-thirds of the shares eligible to vote. Additionally, Maryland law provides, among other things, that the board of directors has broad discretion in adopting stockholders’ rights plans and has the sole power to fix the record date, time and place for special meetings of the stockholders. In addition, Maryland law provides that corporations that:

may elect in their charter or bylaws or by resolution of the board of directors to be subject to all or part of a special subtitle that provides that:

      To date, we have not made any of the elections described above.

      None.

      Our properties are located in 47 states, the District of Columbia and Puerto Rico. As of December 31, 2005, our conventional properties are operated through 17 regional operating centers and a university communities group. Affordable property operations are managed through Aimco Capital and are operated through three regional operating centers. The following table sets forth information on all of our property operations as of December 31, 2005 and 2004:

      At December 31, 2005, we owned an equity interest in and consolidated 619 properties containing 158,548 apartment units, which we refer to as “consolidated.” These consolidated properties contain, on average, 256 apartment units, with the largest property containing 2,899 apartment units. These properties offer residents a range of amenities, including swimming pools, clubhouses, spas, fitness centers, tennis courts and saunas. Many of the apartment units offer features such as vaulted ceilings, fireplaces, washer and dryer hook-ups, cable television, balconies and patios. Additional information on our consolidated properties is contained in “Schedule III, Real Estate and Accumulated Depreciation” in this Annual Report. At December 31, 2005, we held an equity interest in and did not consolidate 264 properties containing 35,269 apartment units, which we refer to as “unconsolidated.” In addition, we provided property management services for third parties owning 52 properties containing 5,246 apartment units, and asset management services for third parties owning 435 properties containing 41,421 apartment units, although in certain cases we may indirectly own generally less than one percent of the operations of such properties through a partnership syndication or other fund.

      Substantially all of our consolidated properties are encumbered by mortgage indebtedness. At December 31, 2005, our consolidated properties were encumbered by aggregate mortgage indebtedness totaling $5,667.2 million (not including $33.7 million of mortgage indebtedness included within liabilities related to assets held for sale), having an aggregate weighted average interest rate of 5.99%. Such mortgage indebtedness was secured by 596 properties with a combined net book value of $8,673.2 million. Included in the 596 properties, we had a total of 50 mortgage loans, with an aggregate principal balance outstanding of $795.5 million, that were each secured by property and cross-collateralized with certain (but not all) other mortgage loans within this group of 50 mortgage loans. See Note 6 of the consolidated financial statements in Item 8 for additional information about our indebtedness.

      See the information under the caption “Legal Matters” in Note 9 of the consolidated financial statements in Item 8 for information regarding legal proceedings, which information is incorporated by reference in this Item 3.

      No matters were submitted to a vote of security holders during the fourth quarter of 2005.

PART II

      Our Common Stock has been listed and traded on the NYSE under the symbol “AIV” since July 22, 1994. The following table sets forth the quarterly high and low sales prices of our Common Stock, as reported on the NYSE, and the dividends declared for the periods indicated:

      On February 28, 2006, the closing price of our Common Stock was $44.31 per share, as reported on the NYSE and there were 96,566,698 shares of Common Stock outstanding, held by 3,459 stockholders of record. The number of holders does not include individuals or entities who beneficially own shares but whose shares are held of record by a broker or clearing agency, but does include each such broker or clearing agency as one recordholder.

      As a REIT, we are required to distribute annually to holders of common stock at least 90% of our “real estate investment trust taxable income,” which, as defined by the Code and United States Department of Treasury regulations, is generally equivalent to net taxable ordinary income. We measure our economic profitability and intend to pay regular dividends to our stockholders based on Funds From Operations, less Capital Replacements during the relevant period. Future payment of dividends are at the discretion of our Board of Directors and will depend on numerous factors including our financial condition, capital requirements, the annual distribution requirements under the provisions of the Code applicable to REITs and such other factors as our Board of Directors deems relevant.

      From time to time, we issue shares of Common Stock in exchange for common and preferred OP Units tendered to the Aimco Operating Partnership for redemption in accordance with the terms and provisions of the agreement of limited partnership of the Aimco Operating Partnership. Such shares are issued based on an exchange ratio of one share for each common OP Unit or the applicable conversion ratio for preferred OP Units. The shares are generally issued in exchange for OP Units in private transactions exempt from registration under the Securities Act of 1933, as amended, pursuant to Section 4(2) thereof. During the three and twelve months ended December 31, 2005, approximately 4,800 and 425,000 shares of Common Stock were issued in exchange for common OP Units. During the three and twelve months ended December 31, 2005, approximately 700 and 1,100 shares of Common Stock were issued in exchange for preferred OP Units.

      The following table summarizes repurchases of our equity securities in the quarter ended December 31, 2005 (1):

      Dividend Payments. Our Credit Agreement includes customary covenants, including a restriction on dividends and other restricted payments, but permits dividends during any four consecutive fiscal quarters in an aggregate amount of up to 95% of our Funds From Operations for such period or such amount as may be necessary to maintain our REIT status.

      The following selected financial data is based on our audited historical financial statements. This information should be read in conjunction with such financial statements, including the notes thereto, and “Management’s Discussion and Analysis of Financial Condition and Results of Operations” included herein or in previous filings with the Securities and Exchange Commission.

Executive Overview

      We are a self-administered and self-managed real estate investment trust, or REIT, engaged in the ownership, acquisition, management and redevelopment of apartment properties. Our property operations are characterized by diversification of product, location and price point. As of December 31, 2005, we owned or managed 1,370 apartment properties containing 240,484 units located in 47 states, the District of Columbia and Puerto Rico. Our primary sources of income and cash are rents associated with apartment leases.

      The key financial indicators that we use in managing our business and in evaluating our financial condition and operating performance are: Funds From Operations, or FFO; FFO less spending for Capital Replacements, or AFFO; same store property operating results; net operating income; net operating income less spending for Capital Replacements, or Free Cash Flow; financial coverage ratios; and leverage as shown on our balance sheet. These terms are defined and described in the sections captioned “Funds From Operations” and “Capital Expenditures” below. The key macro-economic factors and non-financial indicators that affect our financial condition and operating performance are: rates of job growth; single-family and multifamily housing starts; and interest rates.

      Because our operating results depend primarily on income from our properties, the supply and demand for apartments influences our operating results. Additionally, the level of expenses required to operate and maintain our properties, the pace and price at which we redevelop, acquire and dispose of our apartment properties, and the volume and timing of fee transactions affect our operating results. Our cost of capital is affected by the conditions in the capital and credit markets and the terms that we negotiate for our equity and debt financings.

      Our focus in 2005 has been to increase revenue and implement cost management and productivity initiatives, which includes centralizing purchasing, restructuring business processes, using technology to increase efficiency and implementing structured monthly reporting to identify issues and improve effectiveness of spending. We believe that our efforts are having their intended effect, are resulting in a positive trend in certain operating results and are the foundation for improved long-term operating results. These initiatives and others have also resulted in improved asset quality, and we will continue to seek opportunities to reinvest in our properties through capital expenditures and to manage our portfolio through property sales and acquisitions.

      For 2006, our focus will include the following: continue to improve operations so that customer satisfaction and occupancy increase to bring improved profitability; upgrade the quality of our portfolio through portfolio management and redevelopment; increase efficiency through improved business processes and automation; improve balance sheet flexibility; minimize our cost of capital in the face of rising interest rates; and monetize a portion of the value inherent in our properties with increased entitlements.

      The following discussion and analysis of the results of our operations and financial condition should be read in conjunction with the financial statements.

Results of Operations

      We reported net income of $71.0 million and net loss attributable to common stockholders of $17.0 million for the year ended December 31, 2005, compared to net income of $263.5 million and net income attributable to common stockholders of $174.7 million for the year ended December 31, 2004, decreases of $192.5 million and $191.7 million, respectively. These decreases were principally due to the following items, all of which are discussed in further detail within this section:

      These decreases were partially offset by an increase in net operating income associated with property operations, which included increases related to acquisition, newly consolidated and same store properties.

      We reported net income of $263.5 million and net income attributable to common stockholders of $174.7 million for the year ended December 31, 2004, compared to net income of $158.9 million and net income attributable to common stockholders of $65.3 million for the year ended December 31, 2003, increases of $104.6 million and $109.4 million, respectively. These increases were principally due to the following items, all of which are discussed in further detail within this section:

      These increases were partially offset by:

      The following paragraphs discuss these and other items affecting the results of our operations in more detail.

      Our operating income is primarily generated from the operations of our consolidated properties. The principal components within our total consolidated property operations are: consolidated same store properties, which consist of all conventional properties that were owned (and not classified as held for sale) and managed by us, stabilized and consolidated for all comparable periods presented; and other consolidated entities, which primarily include acquisition, newly consolidated, affordable and redevelopment properties.

      The following table summarizes the overall performance of our consolidated properties for the years ended December 31, 2005, 2004 and 2003 (in thousands):

      For the year ended December 31, 2005 compared to the year ended December 31, 2004, net operating income for our consolidated property operations increased by $77.8 million, or 11.5%. This increase was principally due to a $39.3 million increase in consolidated same store net operating income (see further discussion of same store results under the heading “Conventional Same Store Property Operating Results”); a $21.3 million increase related to operations of acquisition properties, which were principally comprised of Palazzo East at Park La Brea and five other properties purchased in 2005 and The Palazzo at Park La Brea and 10 other properties purchased in 2004; an $18.0 million increase related to operations of newly consolidated properties, which are properties that had been previously unconsolidated and accounted for by the equity method

(21 properties first consolidated in 2005 and 42 properties first consolidated in 2004, which includes 24 properties that were consolidated due to the adoption of FASB Interpretation No. 46, Consolidation of Variable Interest Entities, or FIN 46,); a $3.9 million increase related to operations of our affordable properties; and a $2.7 million increase related to the completion of certain redevelopment properties. These increases were offset by $6.4 million of increased property management expenses and $3.3 million of higher net casualty losses in 2005 as compared to 2004, primarily relating to greater hurricane and tropical storm damage that occurred in 2005.

      For the year ended December 31, 2004, compared to the year ended December 31, 2003, net operating income for our consolidated property operations decreased by $19.9 million, or 2.9%. This decrease was principally due to a $40.3 million decrease in consolidated same store net operating income (see further discussion of same store results under the heading “Conventional Same Store Property Operating Results”). Additionally, there was a $6.6 million decrease related to net casualty losses and other costs primarily resulting from hurricanes and tropical storms in the third quarter of 2004, which damaged over 100 of our properties and $4.0 million in higher property management expenses. These decreases were offset by an $18.2 million increase related to operations of newly consolidated properties, which are properties that had been previously unconsolidated and accounted for by the equity method (42 properties first consolidated in 2004 and 12 properties that were first consolidated after the first quarter of 2003) and a $16.0 million increase related to operations of acquisition properties, which were principally comprised of The Palazzo at Park La Brea and 10 other properties purchased in 2004, and three properties purchased in 2003.

Conventional Same Store Property Operating Results

      Same store operating results is a key indicator we use to assess the performance of our property operations and to understand the period over period operations of a consistent portfolio of properties. We define “same store” properties as conventional properties (i) that we manage, (ii) in which our ownership interest exceeds 10%, (iii) the operations of which have been stabilized for all periods presented and (iv) that have not been classified as held for sale. Our share reflects Aimco’s ownership share before minority interest in the Aimco Operating Partnership. To ensure comparability, the information for all periods shown is based on our ownership in the most current period presented in each table. The following tables summarize the conventional rental property operations on a “same store” basis (which is not in accordance with generally accepted accounting principles, or GAAP) and reconcile them to consolidated rental property operations (which is in accordance with GAAP) described in the above comparative discussions (dollars in thousands):

      For the year ended December 31, 2005, compared to the year ended December 31, 2004, our share of same store net operating income increased $32.8 million, or 6.3%. Revenues increased $57.7 million, or 6.1%, primarily due to higher occupancy (up 2.9%), higher average rent (up $16 per unit) and lower bad debt. Expenses increased by $24.9 million, or 6.0%, primarily due to: an increase of $9.1 million in compensation expense related to increased staffing levels to support our initiatives to improve customer service; a $7.2 million increase in utilities due primarily to higher natural gas rates; a $5.5 million increase in real estate taxes; and $2.4 million of increases primarily related to turnover expenses associated with our efforts to increase occupancy.

      For the year ended December 31, 2004, compared to the year ended December 31, 2003, our share of same store net operating income decreased $30.4 million, or 5.1%. Revenues decreased $6.2 million, or 0.6%, primarily due to lower occupancy (down 1.6%), offset by higher utility reimbursements from residents and lower bad debt expense. Expenses increased by $24.1 million, or 5.8%, primarily due to: an increase of $20.0 million in compensation and benefit expense related to a new employee health plan, merit increases and increased staffing levels; an increase of $4.3 million in utilities due to the increase in the cost of natural gas; and an increase of $3.9 million in marketing and administrative expenses associated with our efforts to increase occupancy. These increases were partially offset by a decrease in property taxes related to successful appeals and changes in estimates related to assessments.

      We earn income from property management primarily from certain unconsolidated real estate partnerships for which we are the general partner. The income is primarily in the form of fees generated through property management and other associated activities. Reported revenue from property management decreases as we consolidate real estate partnerships because it is eliminated in consolidation. We expect this trend to continue as we increase our ownership in more of these partnerships or otherwise determine that consolidation is required by GAAP. Additionally, our revenue decreases as properties within our unconsolidated real estate partnerships are sold. Offsetting the revenue earned in property management are the direct expenses associated with property management.

      The following table summarizes the overall performance of our property management business for the years ended December 31, 2005, 2004 and 2003 (in thousands):

      For the year ended December 31, 2005, compared to the year ended December 31, 2004, net operating income from property management decreased by $5.4 million, or 24.0%. For the year ended December 31, 2004, compared to the year ended December 31, 2003, net operating income from property management decreased by $6.9 million, or 23.3%. In both periods the decreases were principally due to an increase in the number of consolidated real estate partnerships (resulting from increased ownership and GAAP consolidation requirements), which required elimination of fee income and associated property-operating expense related to such partnerships and the sales of properties within our unconsolidated partnerships (35 properties in 2005, 53 properties in 2004 and 37 properties in 2003) that had previously generated property management revenues.

      Activity fees are generated from transactional activity including tax credit syndications and redevelopments, dispositions, and refinancings. These transactions occur on varying timetables, thus the income varies from period to period. The majority of these fees are earned in connection with transactions related to affordable properties within the Aimco Capital portfolio. We have a large number of affiliated real estate partnerships for which we have identified a pipeline of transactional opportunities. As a result, we view activity fees as a predictable part of our core business strategy. Asset management revenue is from the financial management of partnerships, rather than management of day-to-day property operations. Asset management revenue includes deferred asset management fees that are recognized once a transaction or improvement in operations has occurred thereby generating available cash. Activity and asset management expenses are the direct expenses associated with transactional activities and asset management.

      The following table summarizes the operating results of our transactional and asset management activities for the years ended December 31, 2005, 2004 and 2003 (in thousands):

      Included in the activity fees and asset management revenues, primarily from affiliates for the years ended December 31, 2005, 2004 and 2003, were $33.3 million, $30.3 million and $18.9 million, respectively, of fees related to affordable properties within the Aimco Capital portfolio.

      For the year ended December 31, 2005, compared to the year ended December 31, 2004, net operating income from activity fees and asset management increased $3.7 million, or 16.3%. This overall increase was principally a result of increased activity fees related to syndication and developer activities of $6.0 million and $3.7 million, respectively, as well as a $1.2 million decrease in expenses associated with these activities. Additionally, we received $3.1 million in promote distributions from an unconsolidated partnership, as a result of us, as general partner, achieving financial returns to the limited partners in excess of established targets. These increases were offset by a $5.2 million decrease in asset management fees and decreases of $3.3 million and $1.9 million in activity fees related to disposition and refinancing activities, respectively.

      For the year ended December 31, 2004, compared to the year ended December 31, 2003, net operating income from activity fees and asset management increased by $11.2 million, or 94.4%. This overall increase was principally a result of increased activity fees related to disposition, refinancing and developer activities of $7.3 million, $2.3 million and $3.0 million, respectively, due to a greater number of transactions in 2004 than in 2003. Additionally, there was an increase of $2.9 million related to the recognition of deferred asset management fees resulting from closed transactions and improved operations. These increases were offset by a $2.1 million decrease in syndication fees and $3.4 million in higher expenses associated with these activities.

      For the year ended December 31, 2005, compared to the year ended December 31, 2004, depreciation and amortization increased $71.5 million, or 21.0%. This increase was principally due to: $34.6 million of additional depreciation on certain real estate assets where the depreciation was adjusted prospectively (see Impairment of Long-Lived Assets in Note 2 of the consolidated financial statements in Item 8); $13.8 million and $8.3 million of additional depreciation related to newly consolidated and acquisition properties, respectively; and $11.0 million from the completion of certain redevelopment properties. Additionally, $4.3 million of the increase was due to a change in estimated useful lives that apply to capitalized payroll and certain indirect costs (see Capital Expenditures and Related Depreciation in Note 2 of the consolidated financial statements in Item 8).

      For the year ended December 31, 2004, compared to the year ended December 31, 2003, depreciation and amortization increased $32.5 million, or 10.5%. This increase was principally due to $8.5 million and $7.2 million of additional depreciation related to the newly consolidated and acquisition properties, respectively, as well as $9.9 million from the completion of certain redevelopment properties. Additionally, $5.9 million of the increase resulted from additional depreciation on certain real estate assets where the depreciation was adjusted prospectively (see Impairment of Long-Lived Assets in Note 2 of the consolidated financial statements in Item 8).

      For the year ended December 31, 2005, compared to the year ended December 31, 2004, general and administrative expenses increased $15.4 million, or 19.9%. This increase was principally due to $14.1 million in higher compensation related to increased staffing levels, increased health care costs, and transition costs associated with the chief financial and chief accounting officer positions. Additionally, at the end of 2005 there was $0.6 million in severance costs related to the restructuring of regional operating centers as a result of property dispositions.

      For the year ended December 31, 2004, compared to the year ended December 31, 2003, general and administrative expenses increased $29.1 million, or 60.3%. This increase was principally due to: $15.5 million in higher compensation related to increased staffing levels, merit increases and variable compensation; $7.7 million related to increased health insurance costs and the effect of a favorable change in 2003 related to our accrual for insurance claims incurred but not reported (IBNR); $3.2 million in increased amortization of restricted stock and stock option compensation; and $3.1 million in legal costs and compliance costs primarily related to the internal control reporting requirements of Section 404 of the Sarbanes-Oxley Act of 2002.

      Other expenses (income), net includes income tax provision/benefit, franchise taxes, risk management activities related to our unconsolidated partnerships and partnership expenses.

      For the year ended December 31, 2005 compared to the year ended December 31, 2004, other expenses (income), net changed $8.2 million from expense of $1.9 million in 2004 to income of $6.3 million in 2005. This change was principally due to an $11.4 million higher income tax benefit recognized in 2005 as compared to 2004, reflecting increased losses of our taxable REIT subsidiaries (see further discussion in Note 10 of the consolidated financial statements in Item 8). In the year ended December 31, 2005, there was a tax benefit of $18.6 million recorded, as compared to $7.2 million in the year ended December 31, 2004. Additionally, we had higher income associated with our risk management activities, primarily due to better workers compensation

claim experience as a result of more focused loss prevention measures. These increases in other income were partially offset by $3.8 million of higher partnership expenses primarily related to increases in professional fees.

      For the year ended December 31, 2004, compared to the year ended December 31, 2003, other expenses (income), net changed $8.9 million from income of $7.0 million in 2003 to expense of $1.9 million in 2004. This change was principally due to a $10.8 million lower income tax benefit recognized in 2004 as compared to 2003, due primarily to an $8.0 million benefit related to the reversal of a deferred income tax asset valuation allowance in 2003 (see further discussion in Note 10 of the consolidated financial statements in Item 8). In the year ended December 31, 2004, there was a tax benefit of $7.2 million recorded, as compared to $18.0 million in the year ended December 31, 2003.

      Interest income consists primarily of interest and accretion on general partner notes receivable from our unconsolidated real estate partnerships. Transactions that result in accretion occur on varying timetables and thus the income generated may vary from period to period.

      For the year ended December 31, 2005, as compared to the year ended December 31, 2004, interest income decreased $0.9 million, or 2.7%. This decrease was principally a result of $3.8 million in lower accretion income, partially offset by higher interest income from money market and interest-bearing accounts due to increased interest rates and higher cash balances.

      For the year ended December 31, 2004, as compared to the year ended December 31, 2003, interest income increased $7.6 million, or 30.9%. This increase was principally a result of $5.0 million in higher interest due from general partner notes receivable, and $3.0 million in higher accretion income.

      For the year ended December 31, 2005, compared to the year ended December 31, 2004, interest expense, which includes the amortization of deferred financing costs, increased $25.8 million, or 7.5%. This increase was principally due to: $16.0 million and $5.0 million resulting from interest on the additional debt related to acquisition and newly consolidated properties, respectively; $17.7 million due to increased borrowings and increased interest rates on corporate and variable rate property debt and other items. These increases were partially offset by: $4.8 million in lower amortization of loan costs, primarily due to corporate debt restructuring in 2004; $8.5 million in higher capitalized interest due to increased redevelopment activity; and a $2.1 million decrease related to the redemption of mandatorily redeemable preferred securities in 2004 and early 2005.

      For the year ended December 31, 2004, compared to the year ended December 31, 2003, interest expense increased $24.8 million, or 7.8%. This increase was principally due to: $9.9 million resulting from interest on the additional debt related to the newly consolidated properties; $9.6 million resulting from interest on the additional debt related to acquisition properties; and a $4.7 million decrease in capitalized interest due to redevelopment properties being placed in service. Additionally, an $8.8 million increase related to the credit facility and term loan (of which $1.8 million was associated with the write-off of deferred loan costs related to the November 2004 modification of the credit facility and term loan and $0.8 million related to the payoff of the indebtedness incurred to complete the acquisition of Casden Properties, Inc) due to higher average principal balances along with a higher weighted average interest rate. The November 2004 modification reduced the spread over LIBOR by an average of 1.25%, which has favorably impacted interest expense related to our revolving credit facility and $300 million term loan. These increases were partially offset by lower weighted average effective interest rates on mortgage debt due to refinancings that occurred in 2003 and 2004.

      When real estate partnerships consolidated in our financial statements make cash distributions to partners in excess of the carrying amount of the minority interest, we record a charge equal to the amount of such distribution, even though there is no economic effect or cost.

      For the year ended December 31, 2005, as compared to the year ended December 31, 2004, deficit distributions to minority partners decreased $5.9 million, or 33.1%. For the year ended December 31, 2004, as compared to the year ended December 31, 2003, deficit distributions to minority partners decreased $2.4 million, or 11.6%. The decrease in both periods was due to reduced levels of distributions being made by the consolidated real estate partnerships as a result of lower refinancing activity and decreased operating results, as well as our increased ownership of such partnerships.

      Gain on dispositions of real estate related to unconsolidated entities and other includes our share of gain related to dispositions of real estate within our unconsolidated real estate partnerships, gain on dispositions of land and other non-depreciable assets and costs related to asset disposal activities.

      For the year ended December 31, 2005, as compared to the year ended December 31, 2004, gain on dispositions of real estate related to unconsolidated entities and other decreased $52.8 million. For the year ended December 31, 2004, as compared to the year ended December 31, 2003, gain on dispositions of real estate related to unconsolidated entities and other increased $66.1 million. The change in both periods was principally due to a $34.6 million gain on the sale of a parcel of land located in Florida and a $17.4 million gain from the sale of one of our unconsolidated core properties, both of which occurred in 2004.

      Changes in the level of gains recognized from period to period reflect the changing level of our disposition activity from period to period. Additionally, gains on properties sold are determined on an individual property basis or in the aggregate for a group of properties that are sold in a single transaction, and are not comparable period to period.

      Minority interest in consolidated real estate partnerships reflects minority partners’ share of operating results of consolidated real estate partnerships. This includes the minority partners’ share of property management fees, interest on notes and other amounts eliminated in consolidation that we charge to such partnerships. For the years ended December 31, 2005, 2004 and 2003, such minority interests had a favorable effect on our consolidated operating results.

      For the year ended December 31, 2005, as compared to the year ended December 31, 2004, the benefit from minority interest in consolidated real estate partnerships decreased $10.3 million. For the year ended December 31, 2004, as compared to the year ended December 31, 2003, the benefit from minority interest in consolidated real estate partnerships increased $16.6 million. The change in both periods was driven by property operating results. During 2005 as compared to 2004 our property operating results improved, thereby reducing the benefit from minority interest. When comparing 2004 to 2003 our property operating results declined, thereby increasing the benefit from minority interest.

      For properties accounted for as held for sale, the results of operations for properties sold during the period or designated as held for sale at the end of the period are generally required to be classified as discontinued operations for all periods presented (see Note 2 of the consolidated financial statements in Item 8 for further policy information). The property-specific components of net earnings that are classified as discontinued operations include all property-related revenues and operating expenses, depreciation expense recognized prior to the classification as held for sale, property-specific interest expense to the extent there is secured debt on the property and the associated minority interest. In addition, any impairment losses on assets held for sale, and the net gain on the eventual disposal of properties held for sale are reported as discontinued operations.

      For the years ended December 31, 2005, 2004, and 2003, income from discontinued operations, net totaled $98.9 million, $213.5 million and $97.2 million, respectively, which includes a loss from operations of $2.0 million in 2005 and income from operations of $9.2 million and $21.4 million in 2004 and 2003, respectively. In 2005, the income from operations included the operating results of 91 properties and one

partnership that were sold or classified as held for sale during 2005. In 2004 and 2003, the income from operations included the operating results of 145 properties and one partnership and 217 properties and one partnership, respectively, that were sold or classified as held for sale in 2003, 2004 and 2005. Due to varying number of properties and the timing of sales, the income from operations is not comparable year to year.

      During 2005, we sold 83 properties and one partnership, resulting in a net gain on sale of approximately $100.9 million (which is net of $4.5 million of related income taxes). Additionally, we recognized $3.8 million in impairment losses on assets sold or held for sale in 2005 and $14.9 million of net recoveries of deficit distributions to minority partners. During 2004, we sold 54 properties, resulting in a net gain on sale of approximately $233.4 million (which is net of $16.0 million of related income taxes). Additionally, we recognized $7.3 million in impairment losses on assets sold or held for sale in 2004 and $3.7 million of net recoveries of deficit distributions to minority partners. During 2003, we sold 72 properties, resulting in a net gain on sale of approximately $89.7 million (which is net of $12.1 million of related taxes). Additionally, we recognized $9.0 million in impairment losses on assets sold or held for sale in 2003 and $8.3 million of net recoveries of deficit distributions to minority partners.

      Changes in the level of gains recognized from period to period reflect the changing level of our disposition activity from period to period. Additionally, gains on properties sold are determined on an individual property basis or in the aggregate for a group of properties that are sold in a single transaction, and are not comparable period to period. See Note 14 of the consolidated financial statements in Item 8 for more details on discontinued operations.

      On March 31, 2004, we recorded a $4.0 million cumulative effect of change in accounting principle related to the adoption of FIN 46. This charge is attributable to our recognition of cumulative losses allocable to minority interest that would otherwise have resulted in minority interest deficits. See Note 2 of the consolidated financial statements in Item 8 for further information.

Critical Accounting Policies and Estimates

      We prepare our consolidated financial statements in accordance with GAAP, which requires us to make estimates and assumptions. We believe that the following critical accounting policies involve our more significant judgments and estimates used in the preparation of our consolidated financial statements.

      Real estate and other long-lived assets to be held and used are stated at cost, less accumulated depreciation and amortization, unless the carrying amount of the asset is not recoverable. If events or circumstances indicate that the carrying amount of a property may not be recoverable, we make an assessment of its recoverability by comparing the carrying amount to our estimate of the undiscounted future cash flows, excluding interest charges, of the property. If the carrying amount exceeds the aggregate undiscounted future cash flows, we recognize an impairment loss to the extent the carrying amount exceeds the estimated fair value of the property.

      Real estate investments are subject to varying degrees of risk. Several factors may adversely affect the economic performance and value of our real estate investments. These factors include:

      Any adverse changes in these and other factors could cause an impairment in our long-lived assets, including real estate and investments in unconsolidated real estate partnerships. Based on periodic tests of recoverability of long-lived assets, for the year ended December 31, 2005, we recorded impairment losses of $3.4 million related to properties to be held and used. For the years ended December 31, 2004 and 2003, we determined that the carrying amount for our properties to be held and used was recoverable and, therefore, we did not record any impairment losses related to such properties.

      Notes receivable from unconsolidated real estate partnerships consist primarily of notes receivable from partnerships in which we are the general partner. The ultimate repayment of these notes is subject to a number of variables, including the performance and value of the underlying real estate property and the claims of unaffiliated mortgage lenders. Our notes receivable include loans extended by us that we carry at the face amount plus accrued interest, which we refer to as “par value notes,” and loans extended by predecessors whose positions we generally acquired at a discount, which we refer to as “discounted notes.”

      We record interest income on par value notes as earned in accordance with the terms of the related loan agreements. We discontinue the accrual of interest on such notes when the notes are impaired, as discussed below, or when there is otherwise significant uncertainty as to the collection of interest. We record income on such nonaccrual loans using the cost recovery method, under which we apply cash receipts first to the recorded amount of the loan; thereafter, any additional receipts are recognized as income.

      We recognize interest income on discounted notes receivable based upon whether the amount and timing of collections are both probable and reasonably estimable. We consider collections to be probable and reasonably estimable when the borrower has entered into certain closed or pending transactions (which include real estate sales, refinancings, foreclosures and rights offerings) that provide a reliable source of repayment. In such instances, we recognize accretion income, on a prospective basis using the effective interest method over the estimated remaining term of the loans, equal to the difference between the carrying amount of the discounted notes and the estimated collectible value. We record income on all other discounted notes using the cost recovery method. For the year ended December 31, 2005, if we had not been able to complete certain transactions, our accretion income would have been lower by $2.5 million. Accretion income recognized in any given period is based on our ability to complete transactions to monetize the notes receivable and the difference between the carrying value and the estimated collectible value of the notes; therefore, accretion income varies on a period by period basis and could be lower or higher than in prior periods.

      We assess the collectibility of notes receivable on a periodic basis, which assessment consists primarily of an evaluation of cash flow projections of the borrower to determine whether estimated cash flows are sufficient to repay principal and interest in accordance with the contractual terms of the note. We recognize impairments on notes receivable when it is probable that principal and interest will not be received in accordance with the contractual terms of the loan. The amount of the impairment to be recognized generally is based on the fair value of the partnership’s real estate that represents the primary source of loan repayment. In certain instances where other sources of cash flow are available to repay the loan, the impairment is measured by discounting the estimated cash flows at the loan’s original effective interest rate.

      During the years ended December 31, 2005 and 2004, we recorded $1.4 million and $1.8 million in net recovery of impairment losses on notes receivable. During the year ended December 31, 2003, we identified and recorded $2.2 million in net impairment losses on notes receivable. We will continue to evaluate the collectibility

of these notes, and we will adjust related allowances in the future due to changes in market conditions and other factors.

      We capitalize costs, including certain indirect costs, incurred in connection with our capital expenditure activities, including redevelopment and construction projects, other tangible property improvements, and replacements of existing property components. Included in these capitalized costs are payroll costs associated with time spent by site employees in connection with the planning, execution and control of all capital expenditure activities at the property level. We characterize as “indirect costs” an allocation of certain department costs, including payroll, at the regional operating center and corporate levels that clearly relate to capital expenditure activities. We capitalize interest, property taxes and insurance during periods in which redevelopment and construction projects are in progress. Costs incurred in connection with capital expenditure activities are capitalized where the costs of the improvements or replacements exceed $250. We charge to expense as incurred costs that do not relate to capital expenditure activities, including ordinary repairs, maintenance, resident turnover costs and general and administrative expenses. See Note 2 — Capital Expenditures and Related Depreciation of the consolidated financial statements in Item 8 for further policy information.

      For the years ended December 31, 2005, 2004 and 2003, for continuing and discontinued operations, we capitalized $18.1 million, $9.5 million and $14.5 million of interest costs, respectively, and $53.3 million, $46.7 million and $45.4 million of site payroll and indirect costs, respectively.

Funds From Operations

      Funds From Operations, or FFO, is a non-GAAP financial measure that we believe, when considered with the financial statements determined in accordance with GAAP, is helpful to investors in understanding our performance because it captures features particular to real estate performance by recognizing that real estate generally appreciates over time or maintains residual value to a much greater extent than do other depreciable assets such as machinery, computers or other personal property. The Board of Governors of the National Association of Real Estate Investment Trusts, or NAREIT, defines FFO as net income (loss), computed in accordance with GAAP, excluding gains from sales of depreciable property, plus depreciation and amortization, and after adjustments for unconsolidated partnerships and joint ventures. Adjustments for unconsolidated partnerships and joint ventures are calculated to reflect FFO on the same basis. We compute FFO for all periods presented in accordance with the guidance set forth by NAREIT’s April 1, 2002 White Paper, which we refer to as the White Paper. We calculate FFO (diluted) by subtracting redemption related preferred stock issuance costs and dividends on preferred stock and adding back dividends/distributions on dilutive preferred securities and interest expense on dilutive mandatorily redeemable convertible preferred securities. FFO should not be considered an alternative to net income or net cash flows from operating activities, as determined in accordance with GAAP, as an indication of our performance or as a measure of liquidity. FFO is not necessarily indicative of cash available to fund future cash needs. In addition, although FFO is a measure used for comparability in assessing the performance of real estate investment trusts, there can be no assurance that our basis for computing FFO is comparable with that of other real estate investment trusts.

      For the years ended December 31, 2005, 2004 and 2003, our FFO is calculated as follows (in thousands):

Notes:

Liquidity and Capital Resources

      Liquidity is the ability to meet present and future financial obligations either through the sale or maturity of existing assets or by the acquisition of additional funds through working capital management. Both the coordination of asset and liability maturities and effective working capital management are important to the maintenance of liquidity. Our primary source of liquidity is cash flow from our operations. Additional sources are proceeds from property sales and proceeds from refinancings of existing mortgage loans and borrowings under new mortgage loans.

      Our principal uses for liquidity include normal operating activities, payments of principal and interest on outstanding debt, capital expenditures, dividends paid to stockholders and distributions paid to partners, and acquisitions of, and investments in, properties. We use our cash provided by operating activities to meet short-term liquidity needs. In the event that the cash provided by operating activities is not sufficient to cover our short-term liquidity demands, we have additional means, such as short-term borrowing availability and proceeds from property sales and refinancings, to help us meet our short-term liquidity demands. We use our revolving credit facility for general corporate purposes and to fund investments on an interim basis. We expect to meet our long-term liquidity requirements, such as debt maturities and property acquisitions, through long-term borrowings, both secured and unsecured, the issuance of debt or equity securities (including OP Units), the sale of properties and cash generated from operations.

      At December 31, 2005, we had $161.7 million in cash and cash equivalents, an increase of $56.4 million from December 31, 2004, which cash is principally from sales and refinancing transactions that has yet to be distributed or applied to the outstanding balance of the revolving credit facility (see Note 8 to the consolidated financial statements in Item 8). At December 31, 2005, we had $284.8 million of restricted cash, primarily consisting of reserves and escrows held by lenders for bond sinking funds, capital expenditures, property taxes and insurance. In addition, cash, cash equivalents and restricted cash are held by partnerships that are not presented on a consolidated basis. The following discussion relates to changes in cash due to operating, investing and financing activities, which are presented in our Consolidated Statements of Cash Flows in Item 8.

      For the year ended December 31, 2005, our net cash provided by operating activities of $355.5 million was primarily from operating income from our consolidated properties, which is affected primarily by rental rates, occupancy levels and operating expenses related to our portfolio of properties. Cash provided by operating activities decreased $10.0 million compared with the year ended December 31, 2004, driven by changes in operating assets and liabilities. The changes in operating assets and liabilities were primarily due to cash used to

reduce current liabilities related to interest and real estate tax accruals, offset by decreases in accounts receivable related to improved collections, and decreases in prepaid expense and restricted cash balances.

      For the year ended December 31, 2005, our net cash used in investing activities of $50.0 million primarily resulted from investments in our existing real estate assets through capital spending as well as the acquisition of Palazzo East at Park La Brea and five other properties (see Note 3 to the consolidated financial statements in Item 8 for further information on acquisitions), partially offset by proceeds received from sales of properties.

      Although we hold all of our properties for investment, we sell properties when they do not meet our investment criteria or are located in areas that we believe do not justify our continued investment when compared to alternative uses for our capital. During the year ended December 31, 2005, we sold 83 consolidated properties and 35 unconsolidated properties. These properties were sold for an aggregate sales price of $960.0 million, of which $764.0 million related to the consolidated properties. The sale of the consolidated properties generated proceeds totaling $718.4 million, after the payment of transaction costs. Our share of the total net proceeds from the sale of the 118 properties, after repayment of existing debt, payment of transaction costs and distributions to limited partners, was $331.8 million, of which $36.4 million related to the unconsolidated properties and was included in our distributions received from investments in unconsolidated real estate partnerships. Sales proceeds were used to repay a portion of our outstanding short-term indebtedness and for other corporate purposes.

      We are currently marketing for sale certain properties that are inconsistent with our long-term investment strategy. Additionally, from time to time, we may market certain properties that are consistent with our long-term investment strategy but offer attractive returns, such as sales to buyers who intend to convert the properties to condominiums. Gross sales proceeds from 2006 dispositions are expected to be $750 million to $950 million, and we plan to use our share of the net proceeds from such dispositions to reduce debt, fund capital expenditures on existing assets, fund property and partnership acquisitions, redeem preferred securities and for other operating needs and corporate purposes.

Capital Expenditures

      We classify all capital spending as Capital Replacements (which we refer to as CR), Capital Improvements (which we refer to as CI), casualties or redevelopment. Non-redevelopment and non-casualty capitalizable expenditures are apportioned between CR and CI based on the useful life of the capital item under consideration and the period we have owned the property (i.e., the portion that was consumed during our ownership of the item represents CR; the portion of the item that was consumed prior to our ownership represents CI).

      For the year ended December 31, 2005, we spent a total of $89.7 million on CR. These are expenditures that represent the share of expenditures that are deemed to replace the consumed portion of acquired capital assets. For the year ended December 31, 2005, we spent a total of $112.0 million, $23.9 million and $140.3 million, respectively, on CI, casualties and redevelopment. CI expenditures represent all non-redevelopment and non-casualty capital expenditures that are made to enhance the value, profitability or useful life of an asset from its original purchase condition. Casualty expenditures represent capitalized costs incurred in connection with casualty losses and are associated with the restoration of the asset. A portion of the restoration costs may be reimbursed by insurance carriers subject to deductibles associated with each loss. Redevelopment expenditures represent expenditures that substantially upgrade the property.

      The table below details our share of actual spending, on both consolidated and unconsolidated real estate partnerships, for CR, CI, casualties and redevelopment for the year ended December 31, 2005 on a per unit and total dollar basis (based on approximately 150,200 ownership equivalent units (excluding non-managed units) weighted for the portion of the period that we owned the property), and reconciles it to our Consolidated Statement of Cash Flows for the same period (in thousands, except per unit amounts).

      Included in the above spending for CI, casualties and redevelopment, was approximately $33.2 million of our share of capitalized site payroll and indirect costs related to these activities for the year ended December 31, 2005.

      We funded all of the above capital expenditures with cash provided by operating activities, working capital, property sales and borrowings under the revolving credit facility.

      For the year ended December 31, 2005, net cash used in financing activities of $249.2 million primarily related to payments on our secured notes payable, payment of our dividends, and redemptions of the Class D Cumulative Preferred Stock and Trust Based Convertible Preferred Securities, which we refer to as TOPRS, partially offset by proceeds from borrowings.

      At December 31, 2005 and 2004, we had $5.7 billion in consolidated mortgage debt outstanding, which included $33.7 million and $419.8 million, respectively, of mortgage debt classified within liabilities related to assets held for sale. During the year ended December 31, 2005, we refinanced or closed mortgage loans on 68 consolidated properties generating $591.1 million of proceeds from borrowings with a weighted average interest rate of 5.02%. Our share of the net proceeds after repayment of existing debt, payment of transaction costs and distributions to limited partners, was $254.1 million. In addition, we closed mortgage loans on 15 unconsolidated properties, with a weighted average interest rate of 4.95%. Our share of the net proceeds from these 15 mortgage loans totaled $26.4 million. We used our total net proceeds from all loans closed of $280.5 million for corporate purposes. We intend to continue to refinance mortgage debt to generate proceeds in amounts exceeding our scheduled amortizations and maturities.

      During the year ended December 31, 2005, we closed five mortgage loans totaling $130.3 million, with an initial weighted average interest rate of 3.27%, to finance our consolidated acquisitions.

      We have an Amended and Restated Senior Secured Credit Agreement with a syndicate of financial institutions, which we refer to as the Credit Agreement. On June 16, 2005, we amended our Credit Agreement, to provide for $100.0 million in additional term loan borrowings. The additional term loan matures on November 2, 2009 and bears interest at a rate of either LIBOR plus 1.75% or a base rate (determined by reference to the federal funds rate or Bank of America’s prime rate) plus 0.25%. The proceeds from the additional term loan were used to repay outstanding revolving loans.

      The aggregate amount of commitments and loans under the Credit Agreement is $850.0 million, comprised of $450.0 million of revolving loan commitments and $400.0 million in term loans. The term loans mature on November 2, 2009 and the revolving loans mature on November 2, 2007. At December 31, 2005, the term loans had an outstanding principal balance of $400.0 million and a weighted average interest rate of 6.18% (based on LIBOR plus 2.00% for the original $300.0 million and LIBOR plus 1.75% for the additional $100.0 million). At December 31, 2005, the revolving loans had an outstanding principal balance of $217.0 million and a weighted average interest rate of 6.26% (based on various weighted average LIBOR and base rate borrowings outstanding with various maturities). The amount available under the revolving credit facility at December 31, 2005 was $208.3 million (after giving effect to $24.7 million outstanding for undrawn letters of credit issued under the revolving credit facility). The proceeds of revolving loans are generally permitted to be used to fund working capital and for other corporate purposes. For more information, see Note 8 of the consolidated financial statements in Item 8.

      During the year ended December 31, 2005, we redeemed all outstanding shares of Class D Cumulative Preferred Stock for $31.3 million in cash.

      As of December 31, 2005, under our shelf registration statement, which was declared effective in April 2004, we had available for issuance approximately $877 million of debt and equity securities and the Aimco Operating Partnership had available for issuance $500 million of debt securities. From time to time we may issue preferred securities in both public offerings and private placements to generate proceeds to be used to redeem higher cost preferred securities, to finance acquisitions of real estate interests and for other corporate purposes.

      Our Board of Directors has, from time to time authorized us to repurchase shares of our outstanding capital stock. In April 2005, our Board of Directors replaced the existing authorization with a new authorization to repurchase up to a total of eight million shares of our Common Stock. These repurchases may be made from time to time in the open market or in privately negotiated transactions, subject to applicable law. During 2005, we did not repurchase any shares of our Common Stock.

Contractual Obligations

      This table summarizes information contained elsewhere in this Annual Report regarding payments due under contractual obligations and commitments as of December 31, 2005 (amounts in thousands):

      In addition, we may enter into commitments to purchase goods and services in connection with the operations of our properties. Those commitments generally have terms of one year or less and reflect expenditure levels comparable to our historical expenditures.

      In addition to the items set forth in “Contractual Obligations” above, we expect to fund any future acquisitions, additional redevelopment projects and capital improvements principally with proceeds from property sales (including tax-free exchange proceeds), short-term borrowings, debt and equity financings and operating cash flows.

      In 2006, we plan to invest between $150 and $200 million in conventional redevelopment projects that will impact approximately 70 properties with nearly 30,000 units. Additionally, in 2006 redevelopment expenditures on affordable properties will be approximately $80 million, predominantly funded by third-party tax credit equity, impacting 20 to 25 properties with more than 3,000 units.

Off-Balance Sheet Arrangements

      We own general and limited partner interests in unconsolidated real estate partnerships, in which our total ownership interests range typically from less than 1% up to 50%. However, based on the provisions of the relevant partnership agreements, we are not deemed to have control of these partnerships sufficient to require or permit consolidation for accounting purposes (see Note 2 of the consolidated financial statements in Item 8). There are no lines of credit, side agreements, or any other derivative financial instruments related to or between our unconsolidated real estate partnerships and us and no material exposure to financial guarantees. Accordingly, our maximum risk of loss related to these unconsolidated real estate partnerships is limited to the aggregate carrying amount of our investment in the unconsolidated real estate partnerships and any outstanding notes

receivable as reported in our consolidated financial statements. See Note 4 of the consolidated financial statements in Item 8 for additional information on our unconsolidated real estate partnerships.

      Our primary market risk exposure relates to changes in interest rates. We are not subject to any foreign currency exchange rate risk or commodity price risk, or any other material market rate or price risks. We use predominantly long-term, fixed-rate non-recourse mortgage debt in order to avoid the refunding and repricing risks of short-term borrowings. We use short-term debt financing and working capital primarily to fund short-term uses and acquisitions and generally expect to refinance such borrowings with cash from operating activities, property sales proceeds, long-term debt or equity financings.

      We had $2,010.6 million of floating rate debt outstanding at December 31, 2005 including debt classified within liabilities related to assets held for sale. Of the total floating rate debt, the major components were floating rate tax-exempt bond financing ($726.1 million), floating rate secured notes ($667.5 million), revolving loans ($217.0 million), and term loans ($400.0 million). Historically, changes in tax-exempt interest rates have been at a ratio of less than 1:1 with changes in taxable interest rates. Floating rate tax-exempt bond financing is benchmarked against the BMA Index, which since 1981 has averaged 68.0% of 30-day LIBOR. If this relationship continues, an increase in the 30-day LIBOR, of 1% (0.68% in tax-exempt interest rates) would result in our income before minority interests and cash flows being reduced by $17.8 million on an annual basis. This would be offset by variable rate interest income earned on certain assets, including cash and cash equivalents and notes receivable, as well as interest that is capitalized on a portion of this variable rate debt incurred in connection with our redevelopment activities. Considering these offsets, the same increase in the 30-day LIBOR would result in our income before minority interests being reduced by $8.9 million on an annual basis. Comparatively, if the 30-day LIBOR had increased by 1% in 2004, our income before minority interests would have been reduced by $6.0 million on an annual basis. The potential reduction of income before minority interests was greater in 2005 as compared to 2004 primarily due to higher floating rate balances resulting from additional borrowings, primarily related to the additional $100 million term loan, revolving loans and secured notes.

      We believe that the fair value of our floating rate secured tax-exempt bond debt and floating rate secured long-term debt as of December 31, 2005 approximate their carrying values. The fair value for our fixed-rate debt agreements was estimated based on the market rate for debt with the same or similar terms. The combined carrying amount of our fixed-rate secured tax-exempt bonds and fixed-rate secured notes payable at December 31, 2005 was $4.3 billion compared to the estimated fair value of $4.4 billion (see Note 2 to the consolidated financial statements in Item 8). If market rates for our fixed-rate debt were higher by 1%, the estimated fair value of our fixed-rate debt would have decreased from $4.4 billion to $4.1 billion. If market rates for our fixed-rate debt were lower by 1%, the estimated fair value of our fixed-rate debt would have increased from $4.4 billion to $4.8 billion.

      The independent registered public accounting firm’s report, consolidated financial statements and schedule listed in the accompanying index are filed as part of this report and incorporated herein by this reference. See “Index to Financial Statements” on page F-1 of this Annual Report.

      None.

      Our management, with the participation of our chief executive officer and chief financial officer, has evaluated the effectiveness of our disclosure controls and procedures (as defined in Rules 13a-15(e) and 15d-15(e) under the Securities Exchange Act of 1934, as amended (the “Exchange Act”)) as of the end of the period covered by this report. Based on such evaluation, our chief executive officer and chief financial officer have concluded that, as of the end of such period, our disclosure controls and procedures are adequate.

Management’s Report on Internal Control Over Financial Reporting

      Our management is responsible for establishing and maintaining adequate internal control over financial reporting. Internal control over financial reporting is defined in Rule 13a-15(f) and 15d-15(f) under the Exchange Act as a process designed by, or under the supervision of, our principal executive and principal financial officers and effected by our Board of Directors, management and other personnel to provide reasonable assurance regarding the reliability of financial reporting and the preparation of financial statements for external purposes in accordance with generally accepted accounting principles and includes those policies and procedures that:

      Because of its inherent limitations, internal control over financial reporting may not prevent or detect misstatements. Projections of any evaluation of effectiveness to future periods are subject to the risks that controls may become inadequate because of changes in conditions, or that the degree of compliance with the policies or procedures may deteriorate.

      Management assessed the effectiveness of our internal control over financial reporting as of December 31, 2005. In making this assessment, management used the criteria set forth by the Committee of Sponsoring Organizations of the Treadway Commission (COSO) in Internal Control-Integrated Framework.

      Based on their assessment, management concluded that, as of December 31, 2005, our internal control over financial reporting is effective.

      Our independent registered public accounting firm has issued an audit report on management’s assessment of our internal control over financial reporting.

      There have been no significant changes in our internal control over financial reporting (as defined in Rules 13a-15(f) and 15d-15(f)) under the Exchange Act) during fourth quarter 2005 that have materially affected, or are reasonably likely to materially affect, our internal control over financial reporting.

Report of Independent Registered Public Accounting Firm

Stockholders and Board of Directors of Apartment Investment and Management Company

We have audited management’s assessment, included in the accompanying Management’s Report on Internal Control Over Financial Reporting, that Apartment Investment and Management Company (the “Company”) maintained effective internal control over financial reporting as of December 31, 2005, based on criteria established in Internal Control — Integrated Framework issued by the Committee of Sponsoring Organizations of the Treadway Commission (the COSO criteria). The Company’s management is responsible for maintaining effective internal control over financial reporting and for its assessment of the effectiveness of internal control over financial reporting. Our responsibility is to express an opinion on management’s assessment and an opinion on the effectiveness of the Company’s internal control over financial reporting based on our audit.

We conducted our audit in accordance with the standards of the Public Company Accounting Oversight Board (United States). Those standards require that we plan and perform the audit to obtain reasonable assurance about whether effective internal control over financial reporting was maintained in all material respects. Our audit included obtaining an understanding of internal control over financial reporting, evaluating management’s assessment, testing and evaluating the design and operating effectiveness of internal control, and performing such other procedures as we considered necessary in the circumstances. We believe that our audit provides a reasonable basis for our opinion.

A company’s internal control over financial reporting is a process designed to provide reasonable assurance regarding the reliability of financial reporting and the preparation of financial statements for external purposes in accordance with generally accepted accounting principles. A company’s internal control over financial reporting includes those policies and procedures that (1) pertain to the maintenance of records that, in reasonable detail, accurately and fairly reflect the transactions and dispositions of the assets of the company; (2) provide reasonable assurance that transactions are recorded as necessary to permit preparation of financial statements in accordance with generally accepted accounting principles, and that receipts and expenditures of the company are being made only in accordance with authorizations of management and directors of the company; and (3) provide reasonable assurance regarding prevention or timely detection of unauthorized acquisition, use, or disposition of the company’s assets that could have a material effect on the financial statements.

Because of its inherent limitations, internal control over financial reporting may not prevent or detect misstatements. Also, projections of any evaluation of effectiveness to future periods are subject to the risk that controls may become inadequate because of changes in conditions, or that the degree of compliance with the policies or procedures may deteriorate.

In our opinion, management’s assessment that Apartment Investment and Management Company maintained effective internal control over financial reporting as of December 31, 2005, is fairly stated, in all material respects, based on the COSO criteria. Also, in our opinion, Apartment Investment and Management Company maintained, in all material respects, effective internal control over financial reporting as of December 31, 2005, based on the COSO criteria.

We also have audited, in accordance with the standards of the Public Company Accounting Oversight Board (United States), the consolidated balance sheets of Apartment Investment and Management Company as of December 31, 2005 and 2004, and the related consolidated statements of income, stockholders’ equity, and cash flows for each of the three years in the period ended December 31, 2005, and our report dated March 6, 2006 expressed an unqualified opinion thereon.

Denver, Colorado

March 6, 2006

      None.

PART III

      The information required by this item is presented under the captions “Board of Directors and Officers,” “Corporate Governance Matters — Code of Ethics” and “Other Matters — Section 16(a) Beneficial Ownership Reporting Compliance” in the proxy statement for our 2006 annual meeting of stockholders and is incorporated herein by reference.

      The information required by this item is presented under the captions “Corporate Governance Matters — Compensation of Directors,” “Corporate Governance Matters — Compensation and Human Resources Committee Interlocks and Insider Participation,” “Compensation and Human Resources Committee Report to Stockholders,” “Summary Compensation Table,” “Option/ SAR Grants in Last Fiscal Year,” “Aggregated Option/ SAR Exercises in Last Fiscal Year and Fiscal Year-End Option/ SAR Values,” “Employment Arrangements” and “Stock Price Performance Graph” in the proxy statement for our 2006 annual meeting of stockholders and is incorporated herein by reference.

      The information required by this item is presented under the captions “Security Ownership of Certain Beneficial Owners and Management” and “Securities Authorized for Issuance Under Equity Compensation Plans” in the proxy statement for our 2006 annual meeting of stockholders and is incorporated herein by reference.

      The information required by this item is presented under the caption “Certain Relationships and Related Transactions” in the proxy statement for our 2006 annual meeting of stockholders and is incorporated herein by reference.

      The information required by this item is presented under the caption “Principal Accountant Fees and Services” in the proxy statement for our 2006 annual meeting of stockholders and is incorporated herein by reference.

PART IV

      (a)(1) The financial statements listed in the Index to Financial Statements on Page F-1 of this report are filed as part of this report and incorporated herein by reference.

      (a)(2) The financial statement schedule listed in the Index to Financial Statements on Page F-1 of this report is filed as part of this report and incorporated herein by reference.

      (a)(3) The Exhibit Index is incorporated herein by reference.

INDEX TO EXHIBITS(1)(2)

SIGNATURES

      Pursuant to the requirements of Section 13 or 15(d) of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned, thereunto duly authorized, on the 8th day of March 2006.

      Pursuant to the requirements of the Securities Exchange Act of 1934, this report has been signed below by the following persons on behalf of the registrant and in the capacities and on the dates indicated.

APARTMENT INVESTMENT AND MANAGEMENT COMPANY

INDEX TO FINANCIAL STATEMENTS

REPORT OF INDEPENDENT REGISTERED PUBLIC ACCOUNTING FIRM

Stockholders and Board of Directors Apartment Investment and Management Company

We have audited the accompanying consolidated balance sheets of Apartment Investment and Management Company as of December 31, 2005 and 2004, and the related consolidated statements of income, stockholders’ equity and cash flows for each of the three years in the period ended December 31, 2005. Our audits also included the financial statement schedule listed in the accompanying Index to Financial Statements. These financial statements and schedule are the responsibility of the Company’s management. Our responsibility is to express an opinion on these financial statements and schedule based on our audits.

We conducted our audits in accordance with the standards of the Public Company Accounting Oversight Board (United States). Those standards require that we plan and perform the audit to obtain reasonable assurance about whether the financial statements are free of material misstatement. An audit includes examining, on a test basis, evidence supporting the amounts and disclosures in the financial statements. An audit also includes assessing the accounting principles used and significant estimates made by management, as well as evaluating the overall financial statement presentation. We believe that our audits provide a reasonable basis for our opinion.

In our opinion, the consolidated financial statements referred to above present fairly, in all material respects, the consolidated financial position of Apartment Investment and Management Company at December 31, 2005 and 2004, and the consolidated results of its operations and its cash flows for each of the three years in the period ended December 31, 2005, in conformity with United States generally accepted accounting principles. Also, in our opinion, the related financial statement schedule, when considered in relation to the basic financial statements taken as a whole, presents fairly, in all material respects the information set forth therein.

As discussed in Note 2 to the consolidated financial statements, in 2004 the Company adopted the provisions of Financial Accounting Standards Board Interpretation No. 46 (revised December 2003), Consolidation of Variable Interest Entities.

We also have audited, in accordance with the standards of the Public Company Accounting Oversight Board (United States), the effectiveness of Apartment Investment and Management Company’s internal control over financial reporting as of December 31, 2005, based on criteria established in Internal Control — Integrated Framework issued by the Committee of Sponsoring Organizations of the Treadway Commission and our report dated March 6, 2006 expressed an unqualified opinion thereon.

Denver, Colorado

March 6, 2006

APARTMENT INVESTMENT AND MANAGEMENT COMPANY

CONSOLIDATED BALANCE SHEETS

As of December 31, 2005 and 2004

(In thousands, except share data)