Use these links to rapidly review the document
TABLE OF CONTENTS

Table of Contents

As filed with the Securities and Exchange Commission on October 2, 2018

Registration No. 333-            

UNITED STATES
SECURITIES AND EXCHANGE COMMISSION
WASHINGTON, D.C. 20549

---

FORM S-3
REGISTRATION STATEMENT
UNDER
THE SECURITIES ACT OF 1933

---

SELECT INCOME REIT
(Exact name of registrant as specified in its charter)

Two Newton Place
255 Washington Street, Suite 300
Newton, Massachusetts 02458-1634
(617) 796-8303
(Address, including zip code, and telephone number, including area code, of registrant's principal executive offices)

---

John C. Popeo
Chief Financial Officer and Treasurer
Select Income REIT
Two Newton Place
255 Washington Street, Suite 300
Newton, Massachusetts 02458-1634
(617) 796-8303
(Name, address, including zip code, and telephone number, including area code, of agent for service)

---

Copy to:
Howard E. Berkenblit
Lindsey A. Getz
Sullivan & Worcester LLP
One Post Office Square
Boston, Massachusetts 02109
(617) 338-2800

---

Approximate date of commencement of proposed sale to the public:
From time to time after the effective date of the Registration Statement as determined by the Registrant.

           If the only securities being registered on this form are being offered pursuant to dividend or interest reinvestment plans, please check the following box. o

           If any of the securities being registered on this form are to be offered on a delayed or continuous basis pursuant to Rule 415 under the Securities Act of 1933, other than securities offered only in connection with dividend or interest reinvestment plans, check the following box. ý

           If this form is filed to register additional securities for an offering pursuant to Rule 462(b) under the Securities Act, please check the following box and list the Securities Act registration statement number of the earlier effective registration statement for the same offering. o

           If this form is a post-effective amendment filed pursuant to Rule 462(c) under the Securities Act, check the following box and list the Securities Act registration statement number of the earlier effective registration statement for the same offering. o

           If this Form is a registration statement pursuant to General Instruction I.D. or a post-effective amendment thereto that shall become effective upon filing with the Commission pursuant to Rule 462(e) under the Securities Act, check the following box. ý

           If this Form is a post-effective amendment to a registration statement filed pursuant to General Instruction I.D. filed to register additional securities or additional classes of securities pursuant to Rule 413(b) under the Securities Act, check the following box. o

           Indicate by check mark whether the registrant is a large accelerated filer, an accelerated filer, a non-accelerated filer, a smaller reporting company, or an emerging growth company. See the definitions of "large accelerated filer," "accelerated filer," "smaller reporting company," and "emerging growth company" in Rule 12b-2 of the Exchange Act.

           If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 7(a)(2)(B) of the Securities Act. o

---

CALCULATION OF REGISTRATION FEE

(1)

Not specified pursuant to General Instruction II.E. of Form S-3. An indeterminate aggregate initial offering price or number of the securities is being registered as may from time to time be offered at indeterminate prices.

(2)

Exclusive of accrued interest, distributions and dividends, if any.

(3)

In reliance on Rules 456(b) and 457(r) under the Securities Act of 1933, as amended, the Registrant is deferring payment of the registration fee.

   

---

Table of Contents

PROSPECTUS

SELECT INCOME REIT

Common Shares of Beneficial Interest

        We or our selling security holders may offer, issue and sell, from time to time, in one or more offerings common shares of beneficial interest.

        This prospectus describes some of the general terms that may apply to these securities. The specific amounts and terms of the securities to be offered, issued or sold, and the identity of any selling security holders, will be described in the applicable prospectus supplement. The applicable prospectus supplement may also add to, update or change information contained in this prospectus. You should carefully read this prospectus and any accompanying prospectus supplement as well as the documents incorporated by reference in such documents before you decide to invest in these securities.

        We or our selling security holders may offer and sell these securities to or through one or more underwriters, dealers and agents, or directly to purchasers, on a continuous or delayed basis. The prospectus supplement for each offering will describe the terms of the plan of distribution and set forth the names of any underwriters, dealers or agents involved in the sale of the securities. Unless otherwise set forth in the applicable prospectus supplement, we will not receive any proceeds from the sale of securities sold by any selling security holder.

        Our common shares of beneficial interest are listed on The Nasdaq Stock Market LLC, or Nasdaq, under the symbol "SIR."

        Investment in our securities involves risk, including those described under "Risk Factors" beginning on page 2 of this prospectus. You should carefully read and consider these risk factors and the risk factors included in the reports that we file under the Securities Exchange Act of 1934, as amended, in any prospectus supplement relating to specific offerings of securities and in other documents that we file with the Securities and Exchange Commission.

        Neither the Securities and Exchange Commission nor any state securities commission has approved or disapproved of these securities or determined if this prospectus is truthful or complete. Any representation to the contrary is a criminal offense.

The date of this prospectus is October 2, 2018.

---

Table of Contents

TABLE OF CONTENTS

i

---

Table of Contents

ABOUT THIS PROSPECTUS

        References in this prospectus to "we," "us," "our" or "SIR" mean Select Income REIT, unless the context indicates otherwise.

        This prospectus is part of an "automatic shelf" registration statement that we filed with the Securities and Exchange Commission, or the SEC, as a "well-known seasoned issuer" as defined in Rule 405 under the Securities Act of 1933, as amended, or the Securities Act. Under this shelf registration process, we or our selling security holders may, from time to time, offer, issue and sell the securities described in this prospectus in such amounts and on such terms as set forth in a prospectus supplement in one or more offerings.

        This prospectus provides you with a general description of the securities that may be offered, which is not meant to be a complete description of the securities. Each time we offer, issue or sell securities hereunder, or any selling security holder offers or sells securities hereunder, we or such selling security holder, as applicable, will provide a prospectus supplement that contains specific information about the amounts and terms of that offering. The prospectus supplement may also add to, update or change information contained in this prospectus. You should read both this prospectus and any prospectus supplement together with additional information described under the headings "Where You Can Find More Information" and "Information Incorporated by Reference." If there is any inconsistency between the information in this prospectus and any applicable prospectus supplement, you should rely on the information in the applicable prospectus supplement.

        You should rely only on the information provided or incorporated by reference in this prospectus or any relevant prospectus supplement. We have not authorized anyone to provide you with different information. If anyone provides you with different or inconsistent information, you should not rely on it. Neither we nor any selling security holder will make an offer of the securities in any jurisdiction where it is unlawful. You should assume that the information in this prospectus and any relevant prospectus supplement, as well as the information in any document incorporated or deemed to be incorporated into this prospectus and any relevant prospectus supplement is accurate only as of the date of the documents containing the information.

OUR COMPANY

        We are a real estate investment trust, or REIT, organized under Maryland law that has qualified to be taxed as a REIT under the Internal Revenue Code of 1986, as amended, or the IRC. We and our subsidiaries primarily own properties that are primarily net leased to single tenants. We have no employees. Services which would otherwise be provided to us by employees are provided by The RMR Group LLC, our manager, or RMR LLC, and by our managing trustees and officers. As of June 30, 2018, our consolidated portfolio consisted of 367 buildings, leasable land parcels and easements with approximately 45.7 million rentable square feet. As of June 30, 2018, we also owned 45,000,000 common shares of beneficial interest, $.01 par value per share, of Industrial Logistics Properties Trust, or ILPT, or approximately 69.2% of ILPT's outstanding common shares as of such date.

        As described in our Current Report on Form 8-K dated September 14, 2018, or the September 2018 Form 8-K, on September 14, 2018, we entered an Agreement and Plan of Merger, or the Merger Agreement, with Government Properties Income Trust, a Maryland REIT, or GOV, and GOV's wholly owned subsidiary, GOV MS REIT, a Maryland REIT, or Merger Sub, pursuant to which we have agreed to merge with and into Merger Sub, with Merger Sub continuing as the surviving entity in the merger, or the Merger. We expect that immediately after the Merger, Merger Sub will merge with and into GOV, with GOV as the surviving entity, and GOV will change its name to "Office Properties Income Trust". Pursuant to the terms and subject to the conditions and limitations set forth in the Merger Agreement, at the effective time of the Merger, each of our issued and outstanding common shares will be converted into the right to receive 1.04 newly issued common shares of beneficial

1

---

Table of Contents

interest, $.01 par value per share, of GOV, subject to adjustment as described in the Merger Agreement with cash paid in lieu of fractional shares. Pursuant to the Merger Agreement, we and GOV have agreed that, prior to the effective time of the Merger, GOV will sell, for cash consideration, the 24,918,421 of our common shares beneficially owned by GOV, or the Secondary Sale, and we will, subject to the satisfaction or waiver of certain conditions, declare and, at least one business day prior to the Merger, pay a pro rata distribution to our shareholders of the 45,000,000 common shares of ILPT that we own, or the ILPT Distribution. The foregoing is a summary of the Merger Agreement, the Merger, the Secondary Sale and the ILPT Distribution and does not contain all of the information that may be important to you. For a complete description of the Merger Agreement, the Merger, the Secondary Sale and the ILPT Distribution, please refer to the September 2018 Form 8-K, which has previously been filed with the SEC and is incorporated by reference into this prospectus, and this summary is qualified in its entirety thereby. See "Where You Can Find More Information".

        Our principal executive offices are located at Two Newton Place, 255 Washington Street, Suite 300, Newton, Massachusetts 02458-1634, and our telephone number is (617) 796-8303. Our website is www.sirreit.com. The content of our website, and any information that is linked to our website (other than our filings with the SEC that are expressly incorporated by reference, as set forth under "Information Incorporated by Reference"), is not incorporated by reference in this prospectus, and you should not consider it a part of this prospectus.

RISK FACTORS

        Investing in our securities involves risks. You should carefully review the risk factors contained under the heading "Risk Factors" in our Annual Report on Form 10-K for the fiscal year ended December 31, 2017, or our Annual Report, and any risk factors that we may describe in our Quarterly Reports on Form 10-Q or Current Reports on Form 8-K filed subsequently to our Annual Report, which risk factors are incorporated by reference in this prospectus, the information contained under the heading "Warning Concerning Forward Looking Statements" in this prospectus or under any similar heading in any applicable prospectus supplement or in any document incorporated herein or therein by reference, any specific risk factors discussed under the caption "Risk Factors" in any applicable prospectus supplement or in any document incorporated herein or therein by reference and the other information contained in, or incorporated by reference in, this prospectus or any applicable prospectus supplement before making an investment decision. If any such risks occur, our business, financial condition or results of operations could be materially harmed, the market price of our securities could decline and you could lose all or part of your investment.

WARNING CONCERNING FORWARD LOOKING STATEMENTS

        THIS PROSPECTUS, INCLUDING THE DOCUMENTS THAT ARE INCORPORATED HEREIN BY REFERENCE, CONTAINS STATEMENTS THAT CONSTITUTE FORWARD LOOKING STATEMENTS WITHIN THE MEANING OF THE PRIVATE SECURITIES LITIGATION REFORM ACT OF 1995 AND OTHER SECURITIES LAWS. ALSO, WHENEVER WE USE WORDS SUCH AS "BELIEVE", "EXPECT", "ANTICIPATE", "INTEND", "PLAN", "ESTIMATE", "WILL", "MAY" AND NEGATIVES OR DERIVATIVES OF THESE OR SIMILAR EXPRESSIONS, WE ARE MAKING FORWARD LOOKING STATEMENTS. THESE FORWARD LOOKING STATEMENTS ARE BASED UPON OUR PRESENT INTENT, BELIEFS OR EXPECTATIONS, BUT FORWARD LOOKING STATEMENTS ARE NOT GUARANTEED TO OCCUR AND MAY NOT OCCUR. FORWARD LOOKING STATEMENTS RELATE TO VARIOUS ASPECTS OF OUR BUSINESS, INCLUDING:

•

OUR AND GOV'S ABILITY TO COMPLETE THE TRANSACTIONS CONTEMPLATED BY THE MERGER AGREEMENT, INCLUDING THE MERGER, THE SECONDARY SALE AND THE ILPT DISTRIBUTION,

2

---

Table of Contents

•

THE LIKELIHOOD THAT OUR TENANTS WILL PAY RENT OR BE NEGATIVELY AFFECTED BY CYCLICAL ECONOMIC CONDITIONS,



•

THE LIKELIHOOD THAT OUR TENANTS WILL RENEW OR EXTEND THEIR LEASES OR THAT WE WILL BE ABLE TO OBTAIN REPLACEMENT TENANTS,



•

OUR ACQUISITIONS OF PROPERTIES,



•

OUR SALES OF PROPERTIES,



•

OUR ABILITY TO COMPETE FOR ACQUISITIONS AND TENANCIES EFFECTIVELY,



•

THE LIKELIHOOD THAT OUR RENTS WILL INCREASE WHEN WE RENEW OR EXTEND OUR LEASES, WHEN WE ENTER NEW LEASES, OR WHEN OUR RENTS RESET, INCLUDING RENT RESETS AT OUR SUBSIDIARY, ILPT'S, HAWAII PROPERTIES,



•

OUR ABILITY TO PAY DISTRIBUTIONS TO OUR SHAREHOLDERS AND TO SUSTAIN THE AMOUNT OF SUCH DISTRIBUTIONS,



•

THE FUTURE AVAILABILITY OF BORROWINGS UNDER OUR REVOLVING CREDIT FACILITY OR ILPT'S REVOLVING CREDIT FACILITY,



•

OUR POLICIES AND PLANS REGARDING INVESTMENTS, FINANCINGS AND DISPOSITIONS,



•

OUR ABILITY TO RAISE DEBT OR EQUITY CAPITAL,



•

OUR ABILITY TO PAY INTEREST ON AND PRINCIPAL OF OUR DEBT,



•

OUR ABILITY TO APPROPRIATELY BALANCE OUR USE OF DEBT AND EQUITY CAPITAL,



•

OUR CREDIT RATINGS,



•

OUR EXPECTATION THAT OUR SHAREHOLDERS WILL BENEFIT FROM OUR OWNERSHIP INTEREST IN AND OTHER RELATIONSHIPS WITH ILPT,



•

OUR EXPECTATION THAT WE BENEFIT FROM OUR OWNERSHIP INTEREST IN AND OTHER RELATIONSHIPS WITH THE RMR GROUP INC., OR RMR INC.,



•

OUR EXPECTATION THAT WE BENEFIT FROM OUR OWNERSHIP INTEREST IN AND OTHER RELATIONSHIPS WITH AFFILIATES INSURANCE COMPANY, OR AIC, AND FROM OUR PARTICIPATION IN INSURANCE PROGRAMS ARRANGED BY AIC,



•

OUR QUALIFICATION FOR TAXATION AS A REIT, AND ILPT'S ABILITY TO QUALIFY AND MAINTAIN ITS QUALIFICATION FOR TAXATION AS A REIT,



•

THE CREDIT QUALITIES OF OUR TENANTS, AND



•

OTHER MATTERS.

        OUR ACTUAL RESULTS MAY DIFFER MATERIALLY FROM THOSE CONTAINED IN OR IMPLIED BY OUR FORWARD LOOKING STATEMENTS AS A RESULT OF VARIOUS FACTORS. FACTORS THAT COULD HAVE A MATERIAL ADVERSE EFFECT ON OUR FORWARD LOOKING STATEMENTS AND UPON OUR BUSINESS, RESULTS OF OPERATIONS, FINANCIAL CONDITION, FUNDS FROM OPERATIONS ATTRIBUTED TO US, NORMALIZED FUNDS FROM OPERATIONS ATTRIBUTED TO US, NET OPERATING INCOME, CASH FLOWS, LIQUIDITY AND PROSPECTS INCLUDE, BUT ARE NOT LIMITED TO:

•

THE IMPACT OF CONDITIONS AND CHANGES IN THE ECONOMY AND THE CAPITAL MARKETS ON US AND OUR TENANTS,

3

---

Table of Contents

•

COMPETITION WITHIN THE REAL ESTATE INDUSTRY, PARTICULARLY IN THOSE MARKETS IN WHICH OUR PROPERTIES ARE LOCATED,



•

COMPLIANCE WITH, AND CHANGES TO, FEDERAL, STATE AND LOCAL LAWS AND REGULATIONS, ACCOUNTING RULES, TAX LAWS AND SIMILAR MATTERS,



•

LIMITATIONS IMPOSED ON OUR BUSINESS AND OUR ABILITY TO SATISFY COMPLEX RULES IN ORDER FOR US TO QUALIFY FOR TAXATION AS A REIT FOR U.S. FEDERAL INCOME TAX PURPOSES,



•

ACTUAL AND POTENTIAL CONFLICTS OF INTEREST WITH OUR RELATED PARTIES, INCLUDING OUR MANAGING TRUSTEES, RMR LLC, RMR INC., ILPT, GOV, AIC AND OTHERS AFFILIATED WITH THEM, AND



•

ACTS OF TERRORISM, OUTBREAKS OF SO CALLED PANDEMICS OR OTHER MANMADE OR NATURAL DISASTERS BEYOND OUR CONTROL.

FOR EXAMPLE:

•

THE CLOSING OF OUR MERGER WITH GOV IS SUBJECT TO THE SATISFACTION OR WAIVER OF CONDITIONS, INCLUDING THE RECEIPT OF REQUISITE APPROVALS BY OUR AND GOV'S SHAREHOLDERS AND THE COMPLETION OF THE SECONDARY SALE AND THE ILPT DISTRIBUTION. WE CANNOT BE SURE THAT ANY OR ALL OF SUCH CONDITIONS WILL BE SATISFIED OR WAIVED. ACCORDINGLY, THE MERGER MAY NOT CLOSE WHEN EXPECTED OR AT ALL, OR THE TERMS OF THE MERGER AND THE OTHER TRANSACTIONS MAY CHANGE,



•

AS NOTED ABOVE, THE MERGER WILL REQUIRE APPROVAL OF OUR SHAREHOLDERS AND THE ISSUANCE OF GOV COMMON SHARES IN THE MERGER WILL REQUIRE APPROVAL OF THE GOV SHAREHOLDERS. SUCH APPROVALS WILL BE SOLICITED BY A JOINT PROXY STATEMENT/PROSPECTUS INCLUDED AS PART OF THE REGISTRATION STATEMENT ON FORM S-4 FILED BY GOV WITH THE SEC ON SEPTEMBER 28, 2018. THE REGISTRATION STATEMENT ON FORM S-4 MUST BE REVIEWED AND DECLARED EFFECTIVE BY THE SEC BEFORE THE JOINT PROXY STATEMENT/PROSPECTUS CAN BE MAILED TO OUR SHAREHOLDERS AND GOV'S SHAREHOLDERS. THE AMOUNT OF TIME IT TAKES FOR THE SEC TO REVIEW AND DECLARE THE REGISTRATION STATEMENT EFFECTIVE IS BEYOND OUR AND GOV'S CONTROL. ACCORDINGLY, WE CANNOT BE SURE THAT THE MERGER AND THE OTHER TRANSACTIONS WILL BE CONSUMMATED WITHIN A SPECIFIED TIME PERIOD OR AT ALL OR THAT THE TERMS OF THE MERGER AND THE OTHER TRANSACTIONS WILL NOT CHANGE,



•

GOV OWNS A SIGNIFICANT NUMBER OF OUR COMMON SHARES AND ITS ABILITY TO COMPLETE THE SALE OF ALL OF THOSE SHARES AS CONTEMPLATED BY THE MERGER AGREEMENT IS SUBJECT TO MARKET CONDITIONS AND OTHER FACTORS, SOME OF WHICH ARE BEYOND GOV'S AND OUR CONTROL. AS A RESULT, THE SECONDARY SALE MAY BE DELAYED OR MAY NOT BE COMPLETED,



•

THE ILPT DISTRIBUTION IS SUBJECT TO THE SATISFACTION OF SPECIFIED CONDITIONS, INCLUDING AMONG OTHER THINGS, OBTAINING THE REQUISITE SHAREHOLDER APPROVALS WITH RESPECT TO THE MERGER. WE CANNOT BE SURE WHEN OR IF THOSE CONDITIONS WILL BE SATISFIED OR THAT THE ILPT DISTRIBUTION WILL OCCUR,

4

---

Table of Contents

•

COMPLETION OF THE ILPT DISTRIBUTION IS NOT CONDITIONED UPON CONSUMMATION OF THE MERGER. AS A RESULT, THERE IS A RISK THAT THE ILPT DISTRIBUTION WILL BE COMPLETED AND THE MERGER WILL NOT BE CONSUMMATED, LEAVING US A SIGNIFICANTLY SMALLER COMPANY THAT WILL NO LONGER BENEFIT FROM ILPT'S INCOME OR RECEIVE DISTRIBUTIONS FROM ILPT,



•

THE TRANSACTIONS CONTEMPLATED BY THE MERGER AGREEMENT AND THE TERMS THEREOF WERE EVALUATED, NEGOTIATED AND RECOMMENDED TO EACH OF OUR AND GOV'S BOARD OF TRUSTEES BY A SPECIAL COMMITTEE OF OUR AND GOV'S BOARD OF TRUSTEES, RESPECTIVELY, EACH COMPRISED SOLELY OF OUR AND GOV'S DISINTERESTED, INDEPENDENT TRUSTEES, RESPECTIVELY, AND WERE SEPARATELY APPROVED AND ADOPTED BY OUR AND GOV'S INDEPENDENT TRUSTEES AND BY OUR AND GOV'S BOARD OF TRUSTEES, AND UBS SECURITIES LLC AND CITIGROUP GLOBAL MARKETS INC. ACTED AS A FINANCIAL ADVISOR TO US AND GOV, RESPECTIVELY. DESPITE THIS PROCESS, WE COULD BE SUBJECT TO CLAIMS CHALLENGING THE MERGER OR OTHER TRANSACTIONS OR OUR ENTRY INTO THE MERGER AND RELATED AGREEMENTS BECAUSE OF THE MULTIPLE RELATIONSHIPS AMONG US, GOV, ILPT, RMR LLC AND THEIR RELATED PERSONS AND ENTITIES OR OTHER REASONS, AND DEFENDING EVEN MERITLESS CLAIMS COULD BE EXPENSIVE AND DISTRACTING TO MANAGEMENT,



•

OUR ABILITY TO MAKE FUTURE DISTRIBUTIONS TO OUR SHAREHOLDERS AND TO MAKE PAYMENTS OF PRINCIPAL AND INTEREST ON OUR INDEBTEDNESS DEPENDS UPON A NUMBER OF FACTORS, INCLUDING OUR FUTURE EARNINGS, THE CAPITAL COSTS WE INCUR TO LEASE OUR PROPERTIES, OUR WORKING CAPITAL REQUIREMENTS AND OUR RECEIPT OF DISTRIBUTIONS FROM ILPT. WE MAY BE UNABLE TO PAY OUR DEBT OBLIGATIONS OR TO MAINTAIN OUR CURRENT RATE OF DISTRIBUTIONS ON OUR COMMON SHARES AND FUTURE DISTRIBUTIONS MAY BE REDUCED OR ELIMINATED,



•

OUR ABILITY TO GROW OUR BUSINESS AND INCREASE OUR DISTRIBUTIONS DEPENDS IN LARGE PART UPON OUR ABILITY TO BUY PROPERTIES AND LEASE THEM FOR RENTS, LESS THEIR PROPERTY OPERATING COSTS, THAT EXCEED OUR CAPITAL COSTS. WE MAY BE UNABLE TO IDENTIFY PROPERTIES THAT WE WANT TO ACQUIRE OR TO NEGOTIATE ACCEPTABLE PURCHASE PRICES, ACQUISITION FINANCING OR LEASE TERMS FOR NEW PROPERTIES,



•

CONTINGENCIES IN OUR ACQUISITION AND SALE AGREEMENTS MAY NOT BE SATISFIED AND ANY EXPECTED ACQUISITIONS AND SALES MAY NOT OCCUR, MAY BE DELAYED OR THE TERMS OF SUCH TRANSACTIONS MAY CHANGE,



•

RENTS THAT WE CAN CHARGE AT OUR PROPERTIES MAY DECLINE BECAUSE OF CHANGING MARKET CONDITIONS OR OTHERWISE,



•

MOST OF ILPT'S HAWAII PROPERTIES ARE LANDS LEASED FOR RENTS THAT ARE PERIODICALLY RESET BASED ON THEN CURRENT FAIR MARKET VALUES. REVENUES FROM ILPT'S PROPERTIES IN HAWAII HAVE GENERALLY INCREASED DURING OUR AND OUR PREDECESSOR'S AND ILPT'S OWNERSHIP AS THE LEASES FOR THOSE PROPERTIES HAVE BEEN RESET OR RENEWED. ALTHOUGH ILPT EXPECTS THAT RENTS FOR ITS HAWAII PROPERTIES WILL INCREASE IN THE FUTURE, ILPT CANNOT BE SURE THEY WILL. FUTURE RENTS FROM THESE PROPERTIES COULD DECREASE OR NOT INCREASE TO THE EXTENT THEY HAVE IN THE PAST,

5

---

Table of Contents

•

WE MAY NOT SUCCEED IN FURTHER DIVERSIFYING OUR REVENUE SOURCES AND ANY DIVERSIFICATION WE MAY ACHIEVE MAY NOT MITIGATE OUR PORTFOLIO RISKS OR IMPROVE THE SECURITY OF OUR REVENUES OR OUR OPERATING PERFORMANCE,



•

ILPT'S POSSIBLE REDEVELOPMENT OF CERTAIN OF ITS HAWAII PROPERTIES MAY NOT BE REALIZED OR BE SUCCESSFUL,



•

OUR LEASING RELATED OBLIGATIONS MAY COST MORE OR LESS AND MAY TAKE LONGER TO COMPLETE THAN WE EXPECT, AND OUR LEASING RELATED OBLIGATIONS MAY INCREASE,



•

THE UNEMPLOYMENT RATE OR ECONOMIC CONDITIONS IN AREAS WHERE OUR PROPERTIES ARE LOCATED MAY BECOME WORSE IN THE FUTURE. SUCH CIRCUMSTANCES OR OTHER CONDITIONS MAY REDUCE DEMAND FOR LEASING OFFICE AND INDUSTRIAL SPACE. IF THE DEMAND FOR LEASING OFFICE AND INDUSTRIAL SPACE IS REDUCED, WE MAY BE UNABLE TO RENEW LEASES WITH OUR TENANTS AS LEASES EXPIRE OR ENTER INTO NEW LEASES AT RENTAL RATES AS HIGH AS EXPIRING RENTS AND OUR FINANCIAL RESULTS MAY DECLINE,



•

OUR BELIEF THAT THERE IS A LIKELIHOOD THAT TENANTS MAY RENEW OR EXTEND OUR LEASES WHEN THEY EXPIRE WHENEVER THEY HAVE MADE SIGNIFICANT INVESTMENTS IN THE LEASED PROPERTIES, OR BECAUSE THOSE PROPERTIES MAY BE OF STRATEGIC IMPORTANCE TO THEM, MAY NOT BE REALIZED,



•

SOME OF OUR TENANTS MAY NOT RENEW EXPIRING LEASES, AND WE MAY BE UNABLE TO OBTAIN NEW TENANTS TO MAINTAIN OR INCREASE THE HISTORICAL OCCUPANCY RATES OF, OR RENTS FROM, OUR PROPERTIES,



•

WE MAY INCUR SIGNIFICANT COSTS TO PREPARE A PROPERTY FOR A TENANT, PARTICULARLY FOR SINGLE TENANT PROPERTIES,



•

INCREASING DEVELOPMENT OF INDUSTRIAL AND LOGISTICS PROPERTIES MAY REDUCE THE DEMAND FOR, AND ILPT'S RENTS FROM, ILPT'S PROPERTIES,



•

WE INTEND TO CONDUCT OUR BUSINESS ACTIVITIES IN A MANNER THAT WILL AFFORD US REASONABLE ACCESS TO CAPITAL FOR INVESTMENT AND FINANCING ACTIVITIES. HOWEVER, WE MAY NOT SUCCEED IN THIS REGARD AND WE MAY NOT HAVE REASONABLE ACCESS TO CAPITAL,



•

CONTINUED AVAILABILITY OF BORROWINGS UNDER OUR REVOLVING CREDIT FACILITY AND ILPT'S REVOLVING CREDIT FACILITY IS SUBJECT TO US AND ILPT, AS THE CASE MAY BE, SATISFYING CERTAIN FINANCIAL COVENANTS AND OTHER CREDIT FACILITY CONDITIONS THAT WE AND ILPT MAY BE UNABLE TO SATISFY,



•

ACTUAL COSTS UNDER OUR REVOLVING CREDIT FACILITY AND ILPT'S REVOLVING CREDIT FACILITY OR OTHER FLOATING RATE DEBT WILL BE HIGHER THAN LIBOR PLUS A PREMIUM BECAUSE OF FEES AND EXPENSES ASSOCIATED WITH SUCH DEBT,



•

WE MAY BE UNABLE TO REPAY OUR DEBT OBLIGATIONS WHEN THEY BECOME DUE,



•

THE MAXIMUM BORROWING AVAILABILITY UNDER OUR REVOLVING CREDIT FACILITY MAY BE INCREASED TO UP TO $1.85 BILLION IN CERTAIN CIRCUMSTANCES AND THE MAXIMUM BORROWING AVAILABILITY UNDER ILPT'S REVOLVING CREDIT FACILITY MAY BE INCREASED TO UP TO $1.5 BILLION IN CERTAIN CIRCUMSTANCES. HOWEVER, INCREASING THE MAXIMUM BORROWING AVAILABILITY UNDER OUR

6

---

Table of Contents

REVOLVING CREDIT FACILITY OR ILPT'S REVOLVING CREDIT FACILITY IS SUBJECT TO US AND ILPT, AS THE CASE MAY BE, OBTAINING ADDITIONAL COMMITMENTS FROM LENDERS, WHICH MAY NOT OCCUR,

•

WE HAVE THE OPTION TO EXTEND THE MATURITY DATE OF OUR REVOLVING CREDIT FACILITY, AND ILPT HAS THE OPTION TO EXTEND THE MATURITY DATE OF ITS REVOLVING CREDIT FACILITY, UPON PAYMENT OF A FEE AND MEETING OTHER CONDITIONS, RESPECTIVELY, HOWEVER, THE APPLICABLE CONDITIONS MAY NOT BE MET,



•

WE RECEIVED AN ASSESSMENT FROM THE STATE OF WASHINGTON FOR REAL ESTATE EXCISE TAX, INTEREST AND PENALTIES OF $2.8 MILLION ON CERTAIN PROPERTIES WE ACQUIRED IN CONNECTION WITH OUR ACQUISITION OF COLE CORPORATE INCOME TRUST, INC. IN JANUARY 2015. ALTHOUGH WE BELIEVE WE ARE NOT LIABLE FOR THIS TAX AND ARE DISPUTING THIS ASSESSMENT, WE MAY NOT SUCCEED IN HAVING ALL OR ANY PART OF THIS ASSESSMENT NULLIFIED,



•

THE PREMIUMS USED TO DETERMINE THE INTEREST RATE PAYABLE ON OUR REVOLVING CREDIT FACILITY AND ILPT'S REVOLVING CREDIT FACILITY, THE FACILITY FEE PAYABLE ON OUR REVOLVING CREDIT FACILITY AND THE UNUSED FEE PAYABLE ON ILPT'S REVOLVING CREDIT FACILITY ARE BASED ON OUR CREDIT RATINGS AND ILPT'S LEVERAGE, RESPECTIVELY. FUTURE CHANGES IN OUR CREDIT RATINGS AND ILPT'S LEVERAGE MAY CAUSE THE INTEREST AND FEES WE AND ILPT PAY, RESPECTIVELY, TO INCREASE,



•

RMR INC. MAY REDUCE THE AMOUNT OF DISTRIBUTIONS TO ITS SHAREHOLDERS, INCLUDING US,



•

ILPT MAY REDUCE THE AMOUNT OF DISTRIBUTIONS TO ITS SHAREHOLDERS, INCLUDING US, AND INCLUDING AFTER THE ILPT DISTRIBUTION,



•

THE BUSINESS AND PROPERTY MANAGEMENT AGREEMENTS BETWEEN US AND RMR LLC HAVE CONTINUING 20 YEAR TERMS. HOWEVER, THOSE AGREEMENTS PERMIT EARLY TERMINATION IN CERTAIN CIRCUMSTANCES. ACCORDINGLY, WE CANNOT BE SURE THAT THESE AGREEMENTS WILL REMAIN IN EFFECT FOR CONTINUING 20 YEAR TERMS, AND



•

WE BELIEVE THAT OUR RELATIONSHIPS WITH OUR RELATED PARTIES, INCLUDING RMR LLC, RMR INC., ILPT, GOV, AIC AND OTHERS AFFILIATED WITH THEM MAY BENEFIT US AND PROVIDE US WITH COMPETITIVE ADVANTAGES IN OPERATING AND GROWING OUR BUSINESS. HOWEVER, THE ADVANTAGES WE BELIEVE WE MAY REALIZE FROM THESE RELATIONSHIPS MAY NOT MATERIALIZE.

        CURRENTLY UNEXPECTED RESULTS COULD OCCUR DUE TO MANY DIFFERENT CIRCUMSTANCES, SOME OF WHICH ARE BEYOND OUR CONTROL, SUCH AS ACTS OF TERRORISM, NATURAL DISASTERS, CHANGES IN OUR TENANTS' FINANCIAL CONDITIONS, THE MARKET DEMAND FOR LEASED SPACE OR CHANGES IN CAPITAL MARKETS OR THE ECONOMY GENERALLY. MANY OF THESE FACTORS ALSO APPLY TO ILPT AND ITS BUSINESS, OPERATIONS, LIQUIDITY AND FINANCIAL CONDITION, THE REALIZATION OF WHICH COULD MATERIALLY AND ADVERSELY AFFECT US, PARTICULARLY IF ILPT IS UNABLE TO MAKE DISTRIBUTIONS TO ITS SHAREHOLDERS, INCLUDING US.

        THE INFORMATION CONTAINED ELSEWHERE IN THIS PROSPECTUS, AND IN OUR ANNUAL REPORT OR IN OUR OTHER FILINGS WITH THE SEC, INCLUDING UNDER THE CAPTION "RISK FACTORS", OR INCORPORATED HEREIN OR THEREIN, IDENTIFIES OTHER

7

---

Table of Contents

IMPORTANT FACTORS THAT COULD CAUSE DIFFERENCES FROM OUR FORWARD LOOKING STATEMENTS. OUR FILINGS WITH THE SEC ARE AVAILABLE ON THE SEC'S WEBSITE AT WWW.SEC.GOV.

        YOU SHOULD NOT PLACE UNDUE RELIANCE UPON OUR FORWARD LOOKING STATEMENTS.

        EXCEPT AS REQUIRED BY LAW, WE DO NOT INTEND TO UPDATE OR CHANGE ANY FORWARD LOOKING STATEMENTS AS A RESULT OF NEW INFORMATION, FUTURE EVENTS OR OTHERWISE.

STATEMENT CONCERNING LIMITED LIABILITY

        THE ARTICLES OF AMENDMENT AND RESTATEMENT ESTABLISHING SELECT INCOME REIT, DATED MARCH 9, 2012, AS AMENDED, AS FILED WITH STATE DEPARTMENT OF ASSESSMENTS AND TAXATION OF MARYLAND, PROVIDES THAT NO TRUSTEE, OFFICER, SHAREHOLDER, EMPLOYEE OR AGENT OF SELECT INCOME REIT SHALL BE HELD TO ANY PERSONAL LIABILITY, JOINTLY OR SEVERALLY, FOR ANY OBLIGATION OF, OR CLAIM AGAINST, SELECT INCOME REIT. ALL PERSONS DEALING WITH SELECT INCOME REIT IN ANY WAY SHALL LOOK ONLY TO THE ASSETS OF SELECT INCOME REIT FOR THE PAYMENT OF ANY SUM OR THE PERFORMANCE OF ANY OBLIGATION.

8

---

Table of Contents

USE OF PROCEEDS

        Unless otherwise described in a prospectus supplement, we intend to use the net proceeds that we receive from the sale of the securities covered by this prospectus for general business purposes, which may include acquiring and investing in additional properties and the repayment of borrowings under our revolving credit facility or other debt. Until we apply the proceeds from a sale of securities covered by this prospectus to their stated purposes, we may invest those proceeds in short term investments, including repurchase agreements, some or all of which may not be investment grade.

        Unless otherwise set forth in the applicable prospectus supplement, we will not receive any of the proceeds of the sale by any selling security holder of securities covered by this prospectus.

DESCRIPTION OF COMMON SHARES OF BENEFICIAL INTEREST

        The following description of the terms of our common shares of beneficial interest, $.01 par value per share, or common shares, is only a summary. Because it is a summary, it does not contain all of the information that may be important to you. For a complete description, please refer to our declaration of trust and bylaws, which have previously been filed with the SEC and are incorporated by reference into this prospectus, and this summary is qualified in its entirety thereby. See "Where You Can Find More Information." This summary is also subject to and qualified by reference to the description of the particular terms of common shares described in the applicable prospectus supplement.

        Our declaration of trust authorizes us to issue up to an aggregate of 125,000,000 shares of beneficial interest, all of which are currently designated as common shares. As of October 2, 2018, we had 89,550,528 common shares issued and outstanding. As of the date of this prospectus, no other class or series of shares of beneficial interest has been established.

        Our declaration of trust contains a provision permitting our Board of Trustees, without any action by our shareholders, to amend our declaration of trust to increase or decrease the total number of shares of beneficial interest or the number of shares of any class or series that we have authority to issue. Our declaration of trust further authorizes our Board of Trustees to reclassify any unissued shares from time to time by setting the preferences, conversion or other rights, voting powers, restrictions, limitations as to dividends, qualifications or terms or conditions of redemption of our shares of beneficial interest or any new class or series of shares created by our Board of Trustees. We believe that giving these powers to our Board of Trustees will provide us with increased flexibility in structuring possible future financings and acquisitions and in meeting other business needs which might arise. Although our Board of Trustees has no intention at the present time of doing so, it could authorize us to issue a class or series of shares of beneficial interest that could, depending upon the terms of the class or series, delay or prevent a change in control.

        Except as otherwise described in the applicable prospectus supplement, and subject to the preferential rights of any other class or series of shares then outstanding or which may be issued, and to the ownership restrictions described below, all of our common shares are entitled:

•

to receive distributions on our common shares if, as and when authorized by our Board of Trustees and declared by us out of assets legally available for distribution; and



•

to share ratably in our assets legally available for distribution to our shareholders in the event of our liquidation, dissolution or winding up after payment of or adequate provision for all of our known debts and liabilities.

        Subject to the provisions of our declaration of trust regarding the restriction on the transfer of shares of beneficial interest, each outstanding common share entitles the holder to one vote on all matters submitted to a vote of shareholders, including the election of Trustees. Holders of our common shares do not have cumulative voting rights in the election of Trustees.

9

---

Table of Contents

        Holders of our common shares have no preference, conversion, exchange, sinking fund, redemption or appraisal rights, or preemptive rights to subscribe for any of our securities.

        We will describe in the applicable prospectus supplement any material U.S. federal income tax considerations applicable to the common shares offered by such prospectus supplement.

        For additional information about our common shares, including the potential effects that provisions in our declaration of trust and bylaws may have in delaying or preventing a change in our control, see "Description of Certain Provisions of Maryland Law and of Our Declaration of Trust and Bylaws" below.

        The transfer agent and registrar for our common shares is Equiniti Trust Company.

DESCRIPTION OF CERTAIN PROVISIONS OF MARYLAND LAW
AND OF OUR DECLARATION OF TRUST AND BYLAWS

        We are organized as a Maryland REIT. The following is a summary of our declaration of trust and bylaws and material provisions of Maryland law applicable to Maryland REITs, or the Maryland REIT Law. Because it is a summary, it does not contain all the information that may be important to you. If you want more information, you should read our declaration of trust and bylaws, copies of which are filed with the SEC or refer to the provisions of the Maryland REIT Law.

Restrictions on Ownership and Transfer of Shares

        Our declaration of trust provides that no person may own, or be deemed to own by virtue of applicable attribution provisions of the IRC, or beneficially own under Rule 13d-3 under the Securities Exchange Act of 1934, as amended, or the Exchange Act, more than 9.8% in value or number, whichever is more restrictive, of any class or series of our outstanding shares of beneficial interest, including our common shares. Our declaration of trust further prohibits (1) any person from beneficially or constructively owning our shares if that ownership would result in our being "closely held" under Section 856(h) of the IRC or otherwise cause us to fail to qualify for taxation as a REIT and (2) any person from transferring our shares if the transfer would result in our shares being beneficially owned by fewer than 100 persons.

        Our Board of Trustees, in its discretion, may exempt a person, prospectively or retroactively, from the share ownership limitation if, in its discretion, it determines (1) the ownership of shares by such person would not result in our being "closely held" under Section 856(h) of the IRC or otherwise failing to qualify for taxation as a REIT; (2) such person does not and will not own, actually or constructively, an interest in one of our tenants (or a tenant of any entity which we own or control) that would cause us to own, actually or constructively, more than a 9.8% interest in the tenant; (3) the ownership of shares in excess of the ownership limit pursuant to the exception requested would not cause a default under the terms of any contract to which we or any of our subsidiaries are party or reasonably expect to become a party; and (4) the ownership of shares in excess of the ownership limit is in our best interest. In connection with any requested exemption, our Board of Trustees may require such rulings from the IRS or opinions of counsel as it deems advisable in order to determine or ensure our qualification for taxation as a REIT and such representations, undertakings and agreements it deems advisable in order for it to make the foregoing determinations.

        In determining whether to grant an exemption, our Board of Trustees may consider, among other factors, the following:

•

the general reputation and moral character of the person requesting an exemption;



•

whether the person's ownership of shares would be direct or through ownership attribution;

10

---

Table of Contents

•

whether the person's ownership of shares would interfere with the conduct of our business, including our ability to acquire additional properties;



•

whether granting an exemption would adversely affect any of our existing contractual arrangements or business policies;



•

whether the person to whom the exemption would apply has been approved as an owner of us by all regulatory or other governmental authorities that have jurisdiction over us; and



•

whether the person to whom the exemption would apply is attempting a change in control or to affect our policies in a way in which our Board of Trustees, in its discretion, considers adverse to our or our shareholders' best interests.

        Any attempted transfer of our shares which, if effective, would result in our shares being beneficially owned by fewer than 100 persons shall be void ab initio, and the intended transferee shall acquire no rights in such shares.

        If a person attempts a transfer of our shares in violation of the ownership limitations described above, then our Board of Trustees is authorized and empowered to deem that number of shares which would cause the violation (1) to be automatically transferred to a charitable trust for the exclusive benefit of one or more charitable beneficiaries designated by us or (2) to the fullest extent provided by law, to be void ab initio. A transfer to the charitable trust will be deemed to be effective as of the close of business on the business day prior to the date of our Board of Trustees' determination to have such transfer occur or at such other time determined by our Board of Trustees. The prohibited owner will generally not acquire any rights in these excess shares (except to the extent provided below upon sale of the shares), will not benefit economically from ownership of any excess shares, will have no rights to distributions, will not possess any rights to vote and, to the extent permitted by law, will have no claim, cause of action or other recourse against the purported transferor of such shares. Subject to Maryland law, the trustee of the charitable trust will have the authority to rescind as void any vote cast by the proposed transferee prior to our discovery that the shares have been transferred to the trust and to recast the vote in accordance with the desires of the trustee acting for the benefit of the charitable beneficiary. However, if we have already taken irreversible trust action, then the trustee will not have the authority to rescind and recast the vote. Any dividend or other distribution paid prior to our discovery that shares have been transferred to the trust for the charitable beneficiary will be paid by the recipient to the trustee. Any dividend or other distribution authorized but unpaid will be paid when due to the trustee. Any dividend or other distribution paid to the trustee will be held in trust for the charitable beneficiary.

        Unless otherwise directed by our Board of Trustees, within 20 days of receiving notice from us that our shares have been transferred to a charitable trust, or as soon thereafter as is practicable, the trustee will sell the shares and related rights held in the charitable trust to a person designated by the trustee whose ownership of the shares will not violate the ownership limitations set forth in our declaration of trust. Upon this sale, the interest of the charitable beneficiary in the shares sold will terminate and the trustee will distribute the net proceeds of the sale to the prohibited owner and to the charitable beneficiary as follows:

•

the prohibited owner will receive the lesser of:



(1)

the net price paid by the prohibited owner for the shares or, if the prohibited owner did not give value for the shares in connection with the event causing the shares to be held in the charitable trust, for example, in the case of a gift, devise or other similar transaction, the market price of the shares on the day of the event causing the shares to be transferred to the charitable trust, less our and the trustee's costs, expenses and compensation described below; and

11

---

Table of Contents

(2)

the net sales proceeds received by the trustee from the sale or other disposition of the shares held in the charitable trust; and



•

any net sale proceeds in excess of the amount payable to the prohibited owner shall be paid to the charitable beneficiary, less the costs, expenses and compensation of the charitable trust and trustee.

        If, prior to our discovery that shares have been transferred to the charitable trust, a prohibited owner sells those shares, then:

•

those shares will be deemed to have been sold on behalf of the charitable trust; and



•

to the extent that the prohibited owner received an amount for those shares that exceeds the amount that the prohibited owner was entitled to receive from a sale by the trustee, the prohibited owner must pay the excess to the trustee upon demand.

        Also, shares held in the charitable trust will be deemed to have been offered for sale to us, or our designee, at a price per share equal to the lesser of:

•

the price per share in the transaction that resulted in the transfer to the charitable trust or, in the case of a devise, gift or other similar transaction, the market price per share on the day of the event causing that transfer; and



•

the market price on the date we or our designee accepts the offer.

        In either of the above cases, the price per share will be less our and the trustee's costs, expenses and compensation described below.

        We will have the right to accept the offer until the trustee has sold the shares held in the charitable trust. The net proceeds of the sale to us will be distributed to the prohibited owner.

        Any person who acquires or attempts or intends to acquire beneficial or constructive ownership of any shares that will or may violate the foregoing share ownership limitations, or any person who would have owned shares that resulted in a transfer to a charitable trust, is required to immediately give written notice to us of such event, or in the case of such a proposed or attempted transaction, give at least 15 days' prior written notice, and to provide to us such other information as we may request.

        Every owner of 5% or more of any class or series of our shares is required to give written notice to us within 30 days after the end of each taxable year, and also within three business days after we so request, stating the name and address of the owner, the number of shares of each class and series of our shares which the owner beneficially owns and a description of the manner in which those shares are held. Any such owner who holds our shares as nominee for another person who is required to include distributions on our shares in his or her gross income (the actual owner) is required to give written notice to us stating the name and address of the actual owner and the number of each class and series of our shares of the actual owner with respect to whom the holder of our shares is nominee. Each shareholder is required to provide us with such information as we may request, in good faith, in order to determine our qualification for taxation as a REIT, to determine our compliance with other applicable laws or requirements of any governmental authority and compliance with such share ownership limitations.

        Our declaration of trust provides that the trustee of the charitable trust is entitled to reasonable compensation for its services, as determined by agreement between our Board of Trustees and the trustee, and is entitled to be indemnified for its costs and expenses reasonably incurred in connection with conducting its duties and satisfying its obligations under our declaration of trust. Any such compensation, costs and expenses may be funded from the charitable trust or by us and, if funded by us, we are entitled to reimbursement on a first priority basis from the charitable trust.

12

---

Table of Contents

        We are also entitled, without limiting a shareholder's other obligations under our declaration of trust and bylaws, to collect from the charitable trust our costs and expenses incurred in the process of enforcing the ownership limitations contained in our declaration of trust.

        The restrictions in our declaration of trust described above will not preclude the settlement of any transaction entered into through the facilities of any national securities exchange or automated interdealer quotation system. Our declaration of trust provides, however, that the fact that the settlement of any transaction occurs will not negate the effect of any of the foregoing limitations and any transferee in this kind of transaction will be subject to all of the provisions and limitations described above.

        All certificates evidencing our shares and any share statements for our uncertificated shares may bear legends referring to the foregoing restrictions.

        The restrictions on transfer in our declaration of trust are intended to assist with REIT compliance under the IRC and otherwise to promote our orderly governance. These restrictions do not apply to RMR LLC or its affiliates (including GOV).

Trustees

        Our declaration of trust and bylaws provide for a Board of Trustees of five members and that our Board of Trustees may change the number of Trustees, but there may be not less than three Trustees.

        Our declaration of trust divides our Board of Trustees into three classes. At each annual meeting, shareholders elect the successors of the class of Trustees whose term expires at that meeting for a term expiring at the annual meeting held in the third year following the year of their election. We believe that classification of our Board of Trustees helps to assure the continuity of our business strategies and policies. The classified board provision could have the effect of making the replacement of incumbent Trustees more time consuming and difficult. At least two annual meetings of shareholders will generally be required to effect a change in a majority of our Board of Trustees, and any such change will be difficult to attain so long as GOV retains a significant amount of our common shares, unless GOV votes in favor of such change.

        There is no cumulative voting in the election of Trustees. Except as may be mandated by any applicable law or the listing requirements of the principal securities exchange on which our common shares are listed, and subject to the voting rights of any class or series of our shares of beneficial interest which may be hereafter created, (1) a plurality of all the votes cast at a meeting of our shareholders duly called and at which a quorum is present is required to elect a Trustee in an uncontested election of Trustees and (2) a majority of all the votes entitled to be cast for the election of Trustees at a meeting of our shareholders duly called and at which a quorum is present is required to elect a Trustee in a contested election (which is an election at which the number of nominees exceeds the number of Trustees to be elected at such meeting).

        In case of failure to elect Trustees at an annual meeting of shareholders, the incumbent Trustees may hold over and continue to direct the management of our business and affairs. In the event of a vacancy on our Board of Trustees, including a vacancy caused by a resignation of a Trustee or by an increase in the number of Trustees, the vacancy may be filled only by a majority of the remaining Trustees, even if the remaining Trustees do not constitute a quorum, for the remaining term of the class in which the vacancy exists and until a successor is elected and qualifies. Our declaration of trust provides that a Trustee may be removed (1) only for cause, at a meeting of our shareholders properly called for that purpose, by the affirmative vote of holders of not less than 75% of the outstanding shares entitled to be cast in the election of such Trustee, or (2) with or without cause, by the affirmative vote of not less than 75% of the remaining Trustees. This precludes shareholders from removing incumbent Trustees unless cause for removal exists and they can obtain a substantial

13

---

Table of Contents

affirmative vote of our common shares, and obtaining such vote will not be possible so long as GOV retains more than 25% of our voting shares unless GOV votes in favor of such removal.

        Under our bylaws, a Trustee must be at least 21 years of age, not under legal disability, have substantial expertise or experience relevant to our business (as determined by our Board of Trustees), not have been convicted of a felony and meet the qualifications of an Independent Trustee or a Managing Trustee. An "Independent Trustee" is one who is not an employee of our manager, RMR LLC, who is not involved in our day to day activities and who meets the qualifications of an independent director under the applicable rules of the principal securities exchange on which our common shares are listed for trading and the SEC, as those requirements may be amended from time to time. A "Managing Trustee" is one who has been an employee, officer or director of RMR LLC or involved in our day to day activities for at least one year prior to his or her election. A majority of the Trustees holding office shall at all times be Independent Trustees, except for temporary periods due to vacancies. If the number of Trustees, at any time, is set at less than five, at least one Trustee will be a Managing Trustee. So long as the number of Trustees shall be five or greater, at least two Trustees will be Managing Trustees.

Advance Notice of Trustee Nominations and New Business

        Annual Meetings of Shareholders.    Our bylaws provide that nominations of individuals for election to our Board of Trustees and proposals of other business to be considered at an annual meeting of shareholders may be made only (1) in our notice of the meeting, or otherwise properly brought before the meeting by or at the direction of our Board of Trustees, or (2) by a shareholder who is entitled to vote at the meeting, is entitled to make nominations or proposals and has complied with the advance notice procedures set forth in our bylaws.

        Under our bylaws, a shareholder's written notice of nominations of individuals for election to our Board of Trustees or other matters to be considered at an annual meeting of shareholders must be delivered to our Secretary at our principal executive offices not later than 5:00 p.m. (Eastern Time) on the 120th day nor earlier than the 150th day prior to the first anniversary of the date of our proxy statement for the preceding year's annual meeting; provided, however, that if the annual meeting is called for a date that is more than 30 days earlier or later than the first anniversary of the date of the preceding year's annual meeting, the notice must be delivered by not later than 5:00 p.m. (Eastern Time) on the 10th day following the earlier of the day on which (1) notice of the date of the annual meeting is mailed or otherwise made available or (2) public announcement of the date of the annual meeting is first made by us, provided, further, however, that in the case of the annual meeting held in 2019, for a shareholder's written notice to be timely, it shall be delivered to our Secretary at our principal executive offices not later than 5:00 p.m. (Eastern Time) on October 23, 2018 nor earlier than September 23, 2018. Neither the postponement or adjournment of an annual meeting, nor the public announcement of such postponement or adjournment, commences a new time period for the giving of a shareholder's notice.

        Our bylaws set forth procedures for submission of nominations of individuals for election to our Board of Trustees and other proposals by our shareholders for consideration at an annual meeting of shareholders, including, among other things:

•

requiring that any one or more shareholders wishing to make a nomination or proposal of other business have continuously owned our shares of beneficial interest entitled to vote in the election of Trustees or propose other business for at least three years as of the date of the giving of the notice of the proposed nomination or proposal of other business, the record date for determining the shareholders entitled to vote at the meeting and the time of the annual meeting, with the aggregate shares owned by such shareholder(s) as of each such date during such three year period representing at least 1% of our shares of beneficial interest, that the shareholder(s)

14

---

Table of Contents

hold a certificate evidencing the aggregate number of shares of beneficial interest owned at the time of submitting a notice as of each such date, and that the shareholder(s) submit the proposal to our Secretary in accordance with the requirements of our bylaws;

•

providing that the advance notice provisions in our bylaws are the exclusive means for shareholders to make nominations or propose business for consideration at an annual meeting of our shareholders, except to the extent of matters which are required to be presented to our shareholders by applicable law, which have been properly presented in accordance with the requirements of such law;



•

requiring certain information and documentation be provided regarding any proposed nominee for election to our Board of Trustees by the proposing shareholder(s);



•

requiring certain information be provided with respect to any business other than the election of Trustees that the shareholder(s) propose(s) to bring before a meeting of our shareholders;



•

requiring certain information and documentation be provided as to the proposing shareholder(s) and certain of its (their) affiliates; and



•

providing that the proposing shareholder(s) is (are) responsible for ensuring compliance with the advance notice provisions, that any responses of the shareholder(s) to any request for information will not cure any defect in the notice of the proposing shareholder(s) and that neither we, our Board of Trustees, any committee of our Board of Trustees nor any of our officers has any duty to request clarification or updating information or to inform the proposing shareholder(s) of any defect in the notice of the proposing shareholder(s).

        Special Meetings of Shareholders.    With respect to special meetings of shareholders, our bylaws provide that only business brought before the meeting pursuant to our notice of the meeting or otherwise properly brought before the meeting by or at the direction of our Board of Trustees may be considered at such meeting. Nominations of individuals for election to our Board of Trustees may be made at a special meeting of shareholders at which Trustees are to be elected pursuant to our notice of meeting, by or at the direction of our Board of Trustees or, provided that our Board of Trustees has determined that Trustees will be elected at such special meeting, by a shareholder who is a shareholder of record both at the time of giving of the notice provided for in our bylaws through and including the time of the special meeting, who is entitled to vote at the meeting and has complied with the advance notice procedures set forth in our bylaws. Under our bylaws, if we call a special meeting of shareholders for the purpose of electing one or more Trustees, any one or more shareholders may nominate an individual or individuals (as the case may be) for election to our Board of Trustees if the shareholder(s) satisfies the ownership, holding and certificate requirements required by our bylaws, as described above, for submitting nominations for consideration at an annual meeting of shareholders. To be timely, a shareholder's notice must be delivered not earlier than the 150th day prior to such special meeting and not later than 5:00 p.m. (Eastern Time) on the later of (1) the 120th day prior to such special meeting or (2) the 10th day following the day on which public announcement is first made of the date of the special meeting. Neither the postponement or adjournment of a special meeting, nor the public announcement of such postponement or adjournment, shall commence a new time period for the giving of a shareholder's notice.

Meetings of Shareholders; Voting by Shareholders

        Under our declaration of trust and bylaws, our annual meetings of shareholders will be held at a date and time set by our Board of Trustees. Meetings of our shareholders, including the annual meeting and any special meetings, may be called only by our Board of Trustees.

        Whenever shareholders are required or permitted to take any action by a vote, the action may only be taken by a vote at a shareholders meeting. Under our bylaws, shareholders do not have the right to

15

---

Table of Contents

take any action by written consent. With respect to matters brought before a meeting of shareholders other than the election of Trustees, except where a different voting standard is required by any applicable law, the listing requirements of the principal securities exchange on which our common shares are listed or a specific provision of our declaration of trust, 75% of all common shares entitled to vote at the meeting shall be required to approve the matter unless such matter has been previously approved by our Board of Trustees, in which case the vote required for approval is a majority of votes cast at the meeting.

        Under our declaration of trust, subject to the provisions of any class or series of our shares then outstanding, our shareholders are entitled to vote on the following matters: (1) the election of Trustees and the removal of Trustees; (2) any amendment to our declaration of trust, merger or consolidation of us with or into, or sale of all or substantially all our assets to, another entity and our termination, in each case, to the extent a shareholder vote is required under the Maryland REIT Law, provided that such action has first been approved by at least 60% of our Board of Trustees, including 60% of our Independent Trustees; and (3) such other matters with respect to which our Board of Trustees has adopted a resolution declaring that a proposed action is advisable and directing that the matter be submitted to our shareholders for approval or ratification. Our shareholders will also be entitled to vote on such matters as may be required by our declaration of trust, bylaws or applicable law.

Liability and Indemnification of Trustees and Officers

        The Maryland REIT Law permits a Maryland REIT to include in its declaration of trust a provision limiting the liability of its trustees and officers to the REIT and its shareholders for money damages except for liability resulting from (1) actual receipt of an improper benefit or profit in money, property or services or (2) active and deliberate dishonesty by the trustee or officer that was established by a final judgment as being material to the cause of action adjudicated. Our declaration of trust contains a provision which eliminates the liability of our Trustees and officers to the maximum extent permitted by the Maryland REIT Law.

        The Maryland REIT Law also permits a Maryland REIT to indemnify and advance expenses to its trustees, officers, employees and agents to the same extent permitted by the Maryland General Corporation Law, or the MGCL, for directors and officers of Maryland corporations. The MGCL permits a corporation to indemnify its present and former directors and officers, among others, against judgments, penalties, fines, settlements and reasonable expenses actually incurred by them in connection with any proceeding to which they may be made, or are threatened to be made, a party by reason of their service in those capacities. However, a Maryland corporation is not permitted to provide this type of indemnification if the following is established:

•

the act or omission of the director or officer was material to the matter giving rise to the proceeding and (1) was committed in bad faith or (2) was the result of active and deliberate dishonesty;



•

the director or officer actually received an improper personal benefit in money, property or services; or



•

in the case of any criminal proceeding, the director or officer had reasonable cause to believe that the act or omission was unlawful.

        Under Maryland law, a Maryland corporation may not indemnify a director or officer in a suit by the corporation or in its right in which the director or officer was adjudged liable to the corporation or in a suit in which the director or officer was adjudged liable on the basis that a personal benefit was improperly received. A court may order indemnification if it determines that the director or officer is fairly and reasonably entitled to indemnification, even though the director or officer did not meet the prescribed standard of conduct or was adjudged liable on the basis that personal benefit was improperly

16

---

Table of Contents

received. However, indemnification for an adverse judgment in a suit by the corporation or in its right, or for a judgment of liability on the basis that a personal benefit was improperly received, is limited to expenses. The MGCL permits a corporation to advance reasonable expenses to a director or officer upon the corporation's receipt of the following:

•

a written affirmation by the director or officer of his or her good faith belief that he or she has met the standard of conduct necessary for indemnification by the corporation; and



•

a written undertaking by him or her, or on his or her behalf, to repay the amount paid or reimbursed by the corporation if it is ultimately determined that this standard of conduct was not met.

        Our declaration of trust authorizes us, and our bylaws require us, to the maximum extent permitted by Maryland law, to indemnify, without requiring a preliminary determination of ultimate entitlement to indemnification, (1) any present or former Trustee or officer of us or (2) any individual who, while a Trustee or officer of us and, at our request, serves or has served as a trustee, director, officer or partner of another REIT, corporation, partnership, joint venture, trust, employee benefit plan or other enterprise and who is made or threatened to be made a party to a proceeding by reason of his or her service in that capacity and to pay or reimburse their reasonable expenses in advance of final disposition of the proceeding. Our bylaws also permit us to indemnify and advance expenses to any person who served any predecessor of ours in the capacities described above and any present or former shareholder, employee or agent of us or any such predecessor. Except with respect to proceedings to enforce rights to indemnification, we are required to indemnify a Trustee or officer as described in this paragraph in connection with a proceeding initiated by him or her against us only if such proceeding was authorized by our Board of Trustees.

        We have also entered into indemnification agreements with our Trustees and officers providing for procedures for indemnification by us to the maximum extent permitted by Maryland law and advancements by us of certain expenses and costs relating to claims, suits or proceedings arising from their service to us.

        The SEC has expressed the opinion that indemnification of trustees, officers or persons otherwise controlling a company for liabilities arising under the Securities Act is against public policy and is therefore unenforceable.

Shareholder Liability

        Under the Maryland REIT Law, a shareholder is generally not personally liable for the obligations of a REIT formed under Maryland law solely as a result of his or her status as a shareholder. Our declaration of trust provides that no shareholder will be personally liable for any debt, claim, demand, judgment or obligation of any kind of ours by reason of being a shareholder.

        Our declaration of trust and bylaws provide that each shareholder is liable to us for, and shall indemnify and hold harmless us and our affiliates from and against, all costs, expenses, penalties, fines or other amounts, including without limitation, reasonable attorneys' and other professional fees, whether third party or internal, arising from a shareholder's breach of or failure to fully comply with any covenant, condition or provision of our declaration of trust or bylaws (including the advance notice provisions of our bylaws) or any action by or against us in which the shareholder is not the prevailing party, and shall pay such amounts on demand, together with interest on such amounts, which interest will accrue at the lesser of 18% per annum or the maximum amount permitted by law, from the date such costs or other amounts are incurred until the receipt of payment.

17

---

Table of Contents

Disputes by Shareholders

        Our bylaws provide that actions brought against us or any Trustee, officer, manager (including RMR LLC or its successor), agent or employee of ours, by a shareholder, including derivative and class actions, shall, on the demand of any party to such dispute, be resolved through binding arbitration in accordance with the procedures set forth in our bylaws.

Forum for Certain Disputes

        Our bylaws provide that the Circuit Court for Baltimore City, Maryland will be the sole and exclusive forum for (1) any derivative action or proceeding brought on our behalf, (2) any action asserting a claim of breach of a duty owed by any of our Trustees, officers, managers, agents or employees to us or our shareholders, (3) any action asserting a claim against us or any of our Trustees, officers, managers, agents or employees arising pursuant to Maryland law or our declaration of trust or bylaws, including any disputes, claims or controversies brought by or on behalf of any of our shareholders or (4) any action asserting a claim against us or any of our Trustees, officers, managers, agents or employees governed by the internal affairs doctrine of the State of Maryland. Any person or entity purchasing or otherwise acquiring any interest in our shares of beneficial interest is deemed to have notice of and consented to this provision. This choice of forum provision will limit a shareholder's ability to bring a claim in another judicial forum, including in a judicial forum that the shareholder believes is favorable for disputes with us or our Trustees, officers, managers, agents or employees, which may discourage lawsuits against us and our Trustees, officers, managers, agents or employees. This provision of our bylaws does not abrogate or supersede other provisions of our contracts which may require the resolution of such disputes by arbitration.

Transactions with Affiliates

        Our declaration of trust allows us to enter into contracts and transactions of any kind with any person, including any of our Trustees, officers, employees or agents or any person affiliated with them, subject to any express restrictions adopted by our Trustees. Other than general legal principles applicable to self dealing by Trustees and interested Trustee transactions, there are currently no prohibitions in our declaration of trust or bylaws which would prohibit dealings between us and our affiliates.

Regulatory Compliance and Disclosure

        Our bylaws provide that any shareholder who, by virtue of such shareholder's ownership of our shares of beneficial interest or actions taken by the shareholder affecting us, triggers the application of any requirement or regulation of any federal, state, municipal or other governmental or regulatory body on us or any of our subsidiaries shall promptly take all actions necessary and fully cooperate with us to ensure that such requirements or regulations are satisfied without restricting, imposing additional obligations on or in any way limiting the business, assets, operations or prospects of us or any of our subsidiaries. If the shareholder fails or is otherwise unable to promptly take such actions so as to cause satisfaction of such requirements or regulations, such shareholder shall promptly divest a sufficient number of our shares necessary to cause the application of such requirement or regulation to not apply to us or any of our subsidiaries. If the shareholder fails to cause such satisfaction or divest itself of such sufficient number of our shares by not later than the 10th day after triggering such requirement or regulation referred to in the bylaws, then any of our shares beneficially owned by such shareholder at and in excess of the level triggering the application of such requirement or regulation shall, to the fullest extent permitted by law, be deemed to constitute shares held in violation of the ownership limitations set forth in our declaration of trust. Also, our bylaws provide that if the shareholder who triggers the application of any regulation or requirement fails to satisfy the requirements or regulations or to take curative actions within such 10 day period, we may take all other actions which our Board of

18

---

Table of Contents

Trustees deems appropriate to require compliance or to preserve the value of our assets, and we may charge the offending shareholder for our costs and expenses as well as any damages which may result.

        Our bylaws also provide that if a shareholder, by virtue of such shareholder's ownership of our shares of beneficial interest or its receipt or exercise of proxies to vote shares owned by other shareholders, would not be permitted to vote such shareholder's shares or proxies for such shares in excess of a certain amount pursuant to applicable law but our Board of Trustees determines that the excess shares or shares represented by the excess proxies are necessary to obtain a quorum, then such shareholder shall not be entitled to vote any such excess shares or proxies, and instead such excess shares or proxies may, to the fullest extent permitted by law, be voted by RMR LLC or another person designated by our Board of Trustees, in proportion to the total shares otherwise voted on such matter.

Business Combinations

        The MGCL contains a provision which regulates business combinations with interested shareholders. This provision applies to REITs formed under Maryland law like us. Under the MGCL, business combinations such as mergers, consolidations, share exchanges, or, in circumstances specified in the statute, an asset transfer or issuance or reclassification of equity securities between a REIT formed under Maryland law and an interested shareholder or an affiliate of an interested shareholder are prohibited for five years after the most recent date on which the interested shareholder becomes an interested shareholder. Under the MGCL the following persons are deemed to be interested shareholders:

•

any person who beneficially owns, directly or indirectly, 10% or more of the voting power of the trust's outstanding voting shares; or



•

an affiliate or associate of the trust who, at any time within the two year period immediately prior to the date in question, was the beneficial owner, directly or indirectly, of 10% or more of the voting power of the then outstanding voting shares of the trust.

        After the five year prohibition period has ended, a business combination between a trust and an interested shareholder generally must be recommended by the board of trustees of the trust and must receive the following shareholder approvals:

•

the affirmative vote of at least 80% of the votes entitled to be cast by holders of outstanding voting shares of the trust; and



•

the affirmative vote of at least two thirds of the votes entitled to be cast by holders of voting shares other than shares held by the interested shareholder with whom or with whose affiliate or associate the business combination is to be effected or held by an affiliate or associate of the interested shareholder.

        The shareholder approvals discussed above are not required if the trust's shareholders receive the minimum price set forth in the MGCL for their shares and the consideration is received in cash or in the same form as previously paid by the interested shareholder for its shares.

        The foregoing provisions of the MGCL do not apply, however, to business combinations that are approved or exempted by our Board of Trustees prior to the time that the interested shareholder becomes an interested shareholder. A person is not an interested shareholder under the statute if the board of trustees approves in advance the transaction by which that shareholder otherwise would have become an interested shareholder. The board of trustees may provide that its approval is subject to compliance with any terms and conditions determined by the board of trustees. Our Board of Trustees has adopted a resolution that any business combination between us and any other person is exempted from the provisions of the MGCL described in the preceding paragraphs, provided that the business combination is first approved by our Board of Trustees, including the approval of a majority of the

19

---

Table of Contents

members of our Board of Trustees who are not affiliates or associates of the interested shareholder. This resolution, however, may be altered or repealed in whole or in part at any time.

Control Share Acquisitions

        The MGCL contains a provision which regulates control share acquisitions. This provision applies to REITs formed under Maryland law like us. The MGCL provides that control shares of a REIT formed under Maryland law acquired in a control share acquisition have no voting rights except to the extent that the acquisition is approved by a vote of two thirds of the votes entitled to be cast on the matter, excluding shares owned by the acquiror, by officers or by trustees who are employees of the trust. Control shares are voting shares, which, if aggregated with all other such shares previously acquired by the acquiror, or in respect of which the acquiror is able to exercise or direct the exercise of voting power (except solely by virtue of a revocable proxy), would entitle the acquiror to exercise voting power in electing trustees within one of the following ranges of voting power:

•

one tenth or more but less than one third;



•

one third or more but less than a majority; or



•

a majority or more of all voting power.

        An acquiror must obtain the necessary shareholder approval each time it acquires control shares in an amount sufficient to cross one of the thresholds noted above.

        Control shares do not include shares which the acquiring person is entitled to vote as a result of having previously obtained shareholder approval. The MGCL provides for certain exceptions from the definition of control share acquisition.

        A person who has made or proposes to make a control share acquisition, upon satisfaction of the conditions set forth in the statute, including an undertaking to pay the expenses of the meeting, may compel the board of trustees of the trust to call a special meeting of shareholders to be held within 50 days of demand to consider the voting rights of the shares. If no request for a meeting is made, the trust may itself present the matter at any shareholders meeting.

        If voting rights are not approved at the meeting or if the acquiring person does not deliver an acquiring person statement as required by the MGCL, then the trust may redeem for fair value any or all of the control shares, except those for which voting rights have previously been approved. The right of the trust to redeem control shares is subject to conditions and limitations. Fair value is determined, without regard to the absence of voting rights for the control shares, as of the date of the last control share acquisition by the acquiror or of any meeting of shareholders at which the voting rights of the shares are considered and not approved. If voting rights for control shares are approved at a shareholders meeting and the acquiror becomes entitled to vote a majority of the shares entitled to vote, all other shareholders may exercise appraisal rights. The fair value of the shares as determined for purposes of appraisal rights may not be less than the highest price per share paid by the acquiror in the control share acquisition.

        The control share acquisition statute of the MGCL does not apply to the following:

•

shares acquired in a merger, consolidation or share exchange if the trust is a party to the transaction; or



•

acquisitions approved or exempted by a provision in the declaration of trust or bylaws of the trust adopted before the acquisition of shares.

        Our bylaws contain a provision exempting any and all acquisitions by any person of our common shares from the control share acquisition statute. This provision may be amended or eliminated at any time in the future.

20

---

Table of Contents

Subtitle 8

        Subtitle 8 of Title 3 of the MGCL permits a Maryland REIT with a class of equity securities registered under the Exchange Act and at least three independent trustees to elect to be subject, by provision in its declaration of trust or bylaws or a resolution of its board of trustees and notwithstanding any contrary provision in the declaration of trust or bylaws, to any or all of five provisions:

•

a classified board;



•

a two thirds vote requirement for removing a trustee;



•

a requirement that the number of trustees be fixed only by vote of the trustees;



•

a requirement that a vacancy on the board be filled only by the remaining trustees in office and for the replacement trustee to serve for the remainder of the full term of the class of trustees in which the vacancy occurred; and



•

a majority requirement for the calling of a shareholder requested special meeting of shareholders.

        Through other provisions in our declaration of trust and bylaws unrelated to Subtitle 8, we (1) have a classified board, (2) require the affirmative vote of the holders of not less than 75% of all of the votes entitled to be cast in the election of such Trustee for the removal of any Trustee from our Board of Trustees, which removal will be allowed only for cause, or the affirmative vote of not less than 75% of the remaining Trustees for the removal of any Trustee from our Board of Trustees with or without cause, (3) vest in our Board of Trustees the exclusive power to fix the number of Trustees, (4) require that a vacancy on our Board of Trustees be filled only by a majority of the remaining Trustees in office and for the replacement Trustee to serve for the remainder of the full term of the class of Trustees in which the vacancy occurred and (5) vest in our Board of Trustees the exclusive power to call meetings of our shareholders.

Amendments to Our Declaration of Trust, Dissolution and Mergers

        Under the Maryland REIT Law, a Maryland REIT generally cannot amend its declaration of trust, convert or merge unless these actions are approved by at least two thirds of all shares entitled to be cast on the matter. The Maryland REIT Law allows a trust's declaration of trust to set a lower percentage, so long as the percentage is not less than a majority of the votes entitled to be cast on the matter. Our declaration of trust provides for approval of dissolution, amendment of our declaration of trust, conversion and merger by a majority of all votes entitled to be cast on these actions provided the action has been approved by at least 60% of our Board of Trustees, including 60% of our Independent Trustees. Our declaration of trust further provides that if permitted in the future by Maryland law, the majority required to approve any of the foregoing actions which have been approved by at least 60% of our Board of Trustees, including 60% of our Independent Trustees, will be the affirmative vote of a majority of the votes cast on the matter. Under the Maryland REIT Law, a declaration of trust may permit the trustees by a two thirds vote to amend the declaration of trust from time to time to qualify as a REIT under the IRC or the Maryland REIT Law without the affirmative vote or written consent of the shareholders. Our declaration of trust permits this type of action by our Board of Trustees. Our declaration of trust also permits our Board of Trustees to increase or decrease the aggregate number of shares that we may issue and to effect changes in our unissued shares, as described more fully above, and to change our name or the name of any class or series of our shares, in each case without shareholder approval, and provides that, to the extent permitted in the future by Maryland law, our Board of Trustees may amend any other provision of our declaration of trust without shareholder approval. Our declaration of trust and bylaws also provide that our bylaws may only be amended by our Board of Trustees.

21

---

Table of Contents

Anti-Takeover Effect of Maryland Law and of Our Declaration of Trust and Bylaws

        The following provisions in our declaration of trust and bylaws and in Maryland law could delay or prevent a change in our control:

•

the prohibition in our declaration of trust of any shareholder other than excepted holders, including RMR LLC and its affiliates, from owning more than 9.8% in value or number, whichever is more restrictive, of any class or series of our outstanding shares, including our common shares;



•

the division of our Trustees into three classes, with the term of one class expiring each year and, in each case, until a successor is elected and qualifies;



•

shareholder voting rights and standards for the election of Trustees and other matters which generally require larger majorities for approval of actions which are not approved by our Trustees or for the election of Trustees in contested elections than for actions which are approved by our Trustees or for the election of Trustees in uncontested elections;



•

the authority of our Board of Trustees, and not our shareholders, to adopt, amend or repeal our bylaws and to fill vacancies on our Board of Trustees;



•

the fact that only our Board of Trustees, or if there are no Trustees, our officers, may call shareholder meetings and that shareholders are not entitled to act without a meeting;



•

required qualifications for an individual to serve as a Trustee and a requirement that certain of our Trustees be Managing Trustees and other Trustees be Independent Trustees;



•

limitations on the ability of, and various requirements that must be satisfied in order for our shareholders to propose nominees for election to our Board of Trustees and propose other business to be considered at a meeting of our shareholders;



•

the requirement that an individual Trustee may be removed by our shareholders, only with cause, by the affirmative vote of holders of not less than 75% of our common shares entitled to vote in the election of Trustees or, with or without cause, by the affirmative vote of not less than 75% of the remaining Trustees;



•

the authority of our Board of Trustees to adopt certain amendments to our declaration of trust without shareholder approval, including the authority to increase or decrease the number of authorized shares, to create new classes or series of shares (including a class or series of shares that could delay or prevent a transaction or a change in our control that might involve a premium for our shares or otherwise be in the best interests of our shareholders), to increase or decrease the number of shares of any class or series, and to classify or reclassify any unissued shares from time to time by setting or changing the preferences, conversion or other rights, voting powers, restrictions, limitations as to distributions, qualifications or terms or conditions of redemption of our shares or any new class or series of shares created by our Board of Trustees;



•

the requirement that amendments to our declaration of trust may be made only if approved by at least 60% of our Trustees, including 60% of our Independent Trustees;



•

the business combination provisions of the MGCL, if the applicable resolution of our Board of Trustees is rescinded or if our Board's approval of a combination is not obtained;



•

the control share acquisition provisions of the MGCL, if the provision in our bylaws exempting acquisitions of our shares from such provisions is amended or eliminated; and



•

for so long as GOV continues to hold a substantial ownership stake in us, GOV may effectively be able to elect all of the members of our Board of Trustees, including our Independent Trustees, and to control the outcome of any shareholder vote, including with respect to a change in control of us.

22

---

Table of Contents

        In addition, our credit agreement governing our revolving credit and term loan facilities, or our credit agreement, and our shareholders agreement with AIC each also contain change in control provisions, which are further described below, and our business and property management agreements with RMR LLC contain provisions that allow for termination for convenience and termination for a performance reason but require the payment of a termination fee, as further described in those agreements.

        For all of these reasons, among others, our shareholders may be unable to realize a change of control premium for any of our shares they own or otherwise effect a change of our policies.

Liability of Shareholders for Breach of Restrictions on Ownership

        Our credit agreement provides that a change in our control, as defined in that agreement and including RMR LLC ceasing to act as our business and property manager, constitutes a default under such agreement, and a default under the agreement could result in a cross-default under our senior unsecured notes or our other debt. In addition, our shareholders agreement with respect to AIC provides that AIC and the other shareholders of AIC may have rights to acquire our interests in AIC if such an acquisition occurs or if we experience some other change in control. If a breach of the ownership limitations or other provisions of our declaration of trust or bylaws results in a default under our credit agreement or our other debt or a loss of our ownership interests in AIC or other costs or expenses we may incur as a result of the breach, the shareholder or shareholders causing the breach may be liable to us and may be liable to our other shareholders for damages. These damages may be in addition to the loss of beneficial ownership and voting rights of the shares owned by the breaching shareholder or shareholders, as described above, and these damages may be material.

SELLING SECURITY HOLDERS

        Selling security holders are persons or entities that, directly or indirectly, have acquired or will from time to time acquire from us, securities of the type described in this prospectus in various private or other transactions. These selling security holders may from time to time offer and sell the securities pursuant to this prospectus and any applicable prospectus supplement.

        Information regarding the selling security holders, where applicable, will be set forth in a prospectus supplement, in a post-effective amendment, or in filings we make with the SEC under the Exchange Act which are incorporated herein by reference.

PLAN OF DISTRIBUTION

        We or our selling security holders may sell the securities to one or more underwriters for public offering and sale by them or may sell the securities to investors directly or through agents or through a combination of any of these methods of sale. Any underwriter or agent involved in the offer and sale of the securities will be named in the applicable prospectus supplement.

        The distribution of the securities may be effected from time to time in one or more transactions at a fixed price or prices, which may be changed, at market prices prevailing at the time of sale, at prices related to the prevailing market prices or at negotiated prices. We or our selling security holders may engage in at the market offerings into an existing trading market in accordance with Rule 415(a)(4) of the Securities Act. We or our selling security holders also may, from time to time, authorize underwriters acting as our or their agents to offer and sell the securities upon the terms and conditions as are set forth in the applicable prospectus supplement. In connection with the sale of securities, underwriters may be deemed to have received compensation from us or our selling security holders in the form of underwriting discounts or commissions and may also receive commissions from purchasers of securities for whom they may act as agent. Underwriters may sell securities to or through dealers,

23

---

Table of Contents

and the dealers may receive compensation in the form of discounts, concessions or commissions from the underwriters and/or commissions from the purchasers for whom they may act as agent.

        Any underwriting compensation paid by us or our selling security holders to underwriters or agents in connection with the offering of securities offered by means of this prospectus, and any discounts, concessions or commissions allowed by underwriters to participating dealers, will be set forth in the applicable prospectus supplement. Underwriters, dealers and agents participating in the distribution of the securities may be deemed to be underwriters, and any discounts and commissions received by them and any profit realized by them on resale of the securities may be deemed to be underwriting discounts and commissions, under the Securities Act. Underwriters, dealers and agents may be entitled, under agreements entered into with us or our selling security holders, to indemnification against and contribution toward civil liabilities, including liabilities under the Securities Act.

        We or our selling security holders may enter into derivative transactions with third parties, or sell securities not covered by this prospectus to third parties in privately negotiated transactions. If the applicable prospectus supplement indicates, in connection with those derivatives, the third parties may sell securities covered by this prospectus and the applicable prospectus supplement, including in short sale transactions. If so, the third party may use securities pledged by us or our selling security holders or borrowed from us, our selling security holders or others to settle those sales or to close out any related open borrowings of shares, and may use securities received from us or our selling security holders in settlement of those derivatives to close out any related open borrowings of shares. The third party in such sale transactions will be an underwriter and will be identified in the applicable prospectus supplement.

        From time to time, one or more of the selling security holders may pledge, hypothecate or grant a security interest in some or all of the securities owned by them. The pledgees, secured parties or persons to whom the securities have been hypothecated will, upon foreclosure in the event of default, be deemed to be selling security holders. The number of the initial selling security holder's securities offered under this prospectus will decrease as and when any pledgee, secured party or other person takes such actions. The plan of distribution for that selling security holder's securities will otherwise remain unchanged. In addition, a selling security holder may, from time to time, sell the securities short, and, in those instances, this prospectus may be delivered in connection with the short sales and the securities offered under this prospectus may be used to cover short sales.

        We will not receive any proceeds from sales of any securities by the selling security holders. We cannot assure you that the selling security holders will sell all or any portion of their securities, if any, covered by this prospectus.

        In connection with an offering of securities, the underwriters may engage in stabilizing and syndicate covering transactions. These transactions may include overallotments or short sales of the securities, which involves sales of securities in excess of the principal amount of securities to be purchased by the underwriters in an offering, which creates a short position for the underwriters. Covering transactions involve purchases of the securities in the open market after the distribution has been completed in order to cover short positions. Stabilizing transactions consist of certain bids or purchases of securities made for the purpose of preventing or retarding a decline in the market price of the securities while the offering is in progress. Any of these activities may have the effect of preventing or retarding a decline in the market price of the securities being offered. They may also cause the price of the securities being offered to be higher than the price that otherwise would exist in the open market in the absence of these transactions. The underwriters may conduct these transactions on Nasdaq, in the over-the-counter market or otherwise. If the underwriters commence any of these transactions, they may discontinue them at any time.

        The underwriters, dealers and agents that participate in the offer of securities covered by this prospectus, or their affiliates or associates, may engage in transactions with and perform services for us

24

---

Table of Contents

or our selling security holders and our or their affiliates in the ordinary course of business for which they may have received or receive customary fees and reimbursement of expenses.

LEGAL MATTERS

        Unless otherwise specified in connection with the particular offering of any securities, Sullivan & Worcester LLP, as to certain matters of New York law, and Saul Ewing Arnstein & Lehr LLP, as to certain matters of Maryland law, will pass upon the validity of the offered securities for us. Sullivan & Worcester LLP has passed upon certain tax matters in an opinion filed with the registration statement of which this prospectus is a part. Sullivan & Worcester LLP and Saul Ewing Arnstein & Lehr LLP also represent RMR LLC, our manager, ILPT, GOV and certain of their affiliates and related parties on various matters.

EXPERTS

        The consolidated financial statements of Select Income REIT appearing in Select Income REIT's Annual Report (Form 10-K) for the year ended December 31, 2017 including the schedules appearing therein, and the effectiveness of Select Income REIT's internal control over financial reporting as of December 31, 2017, have been audited by Ernst & Young LLP, independent registered public accounting firm, as set forth in their reports thereon included therein, and incorporated herein by reference. Such financial statements are, and audited financial statements to be included in subsequently filed documents will be, incorporated herein in reliance upon the reports of Ernst & Young LLP pertaining to such financial statements and the effectiveness of our internal control over financial reporting as of the respective dates (to the extent covered by consents filed with the Securities and Exchange Commission) given on the authority of such firm as experts in accounting and auditing.

WHERE YOU CAN FIND MORE INFORMATION

        We file annual, quarterly and current reports, proxy statements and other information with the SEC. You may read and copy any reports, statements or other information on file at the SEC's public reference room at 100 F Street, N.E., Washington, D.C. 20549. You can request copies of those documents upon payment of a duplicating fee to the SEC. This prospectus is part of a registration statement and does not contain all of the information set forth in the registration statement. You may call the SEC at 1-800-SEC-0330 for further information on the operation of the public reference rooms. You can review our SEC filings and the registration statement by accessing the SEC's website at www.sec.gov or by accessing our website at www.sirreit.com. Website addresses are included in this prospectus as textual references only and the information in such websites, and any information that is linked to our website (other than our filings with the SEC that are expressly incorporated by reference as set forth under "Information Incorporated by Reference"), is not incorporated by reference into this prospectus or related registration statement.

        Our common shares are traded on Nasdaq under the symbol "SIR," and you can review similar information concerning us at the office of Nasdaq at One Liberty Plaza, 165 Broadway, New York, New York 10006.

25

---

Table of Contents

INFORMATION INCORPORATED BY REFERENCE

        The SEC allows us to "incorporate by reference" the information we file with them, which means that we can disclose important information to you by referring you to those documents. The information incorporated by reference is considered to be part of this prospectus. Statements in this prospectus regarding the contents of any contract or other document may not be complete. You should refer to the copy of the contract or other document filed as an exhibit to the registration statement. Later information filed with the SEC will update and supersede information we have included or incorporated by reference in this prospectus.

        We incorporate by reference the documents listed below and any filings made after the date of the initial filing of the registration statement of which this prospectus is a part made with the SEC under Sections 13(a), 13(c), 14 or 15(d) of the Exchange Act until the offering of the securities made by this prospectus is completed or terminated (other than, in each case, documents or information deemed to have been furnished and not filed in accordance with SEC rules, including under Items 2.02 and 7.01 (and any related Item 9.01) of Form 8-K):

•

our Annual Report;



•

our Quarterly Reports on Form 10-Q for the fiscal quarters ended March 31, 2018 and June 30, 2018;



•

our Current Reports on Form 8-K dated January 11, 2018, February 25, 2018, April 2, 2018, May 16, 2018 and September 14, 2018;



•

the information identified as incorporated by reference under Items 10, 11, 12, 13 and 14 of Part III of our Annual Report from our definitive Proxy Statement for our 2018 Annual Meeting of Shareholders dated February 20, 2018; and



•

the description of our common shares contained in our registration statement on Form 8-A dated June 30, 2016, including any amendments or reports filed for the purpose of updating that description.

        We will provide you with a copy of the information we have incorporated by reference, excluding exhibits other than those which we specifically incorporate by reference in this prospectus. You may obtain this information at no cost by writing or telephoning us at: Two Newton Place, 255 Washington Street, Suite 300, Newton, Massachusetts, 02458-1634, (617) 796-8303, Attention: Investor Relations.

26

---

Table of Contents

PART II
INFORMATION NOT REQUIRED IN PROSPECTUS

Item 14.    Other Expenses of Issuance and Distribution

        Set forth below is an estimate (except in the case of the registration fee) of the amount of fees and expenses (all of which will be borne by the registrant unless otherwise provided in the applicable prospectus supplement) to be incurred in connection with the issuance and distribution of the offered securities, other than underwriting discounts and commissions (if any).

Item 15.    Indemnification of Directors and Officers

        Maryland law applicable to real estate investment trusts, or the Maryland REIT Law, permits a Maryland real estate investment trust, or REIT, to include in its declaration of trust a provision limiting the liability of its trustees and officers to the REIT and its shareholders for money damages except for liability resulting from (1) actual receipt of an improper benefit or profit in money, property or services or (2) active and deliberate dishonesty by the trustee or officer that was established by a final judgment as being material to the cause of action adjudicated. Our declaration of trust contains a provision which eliminates the liability of our Trustees and officers to the maximum extent permitted by the Maryland REIT Law.

        The Maryland REIT Law also permits a Maryland REIT to indemnify and advance expenses to its trustees, officers, employees and agents to the same extent permitted by the Maryland General Corporation Law, or the MGCL, for directors and officers of Maryland corporations. The MGCL permits a corporation to indemnify its present and former directors and officers, among others, against judgments, penalties, fines, settlements and reasonable expenses actually incurred by them in connection with any proceeding to which they may be made, or are threatened to be made, a party by reason of their service in those capacities. However, a Maryland corporation is not permitted to provide this type of indemnification if the following is established:

•

the act or omission of the director or officer was material to the matter giving rise to the proceeding and (1) was committed in bad faith or (2) was the result of active and deliberate dishonesty;



•

the director or officer actually received an improper personal benefit in money, property or services; or

II-1

---

Table of Contents

•

in the case of any criminal proceeding, the director or officer had reasonable cause to believe that the act or omission was unlawful.

        Under Maryland law, a Maryland corporation may not indemnify a director or officer in a suit by the corporation or in its right in which the director or officer was adjudged liable to the corporation or in a suit in which the director or officer was adjudged liable on the basis that a personal benefit was improperly received. A court may order indemnification if it determines that the director or officer is fairly and reasonably entitled to indemnification, even though the director or officer did not meet the prescribed standard of conduct or was adjudged liable on the basis that personal benefit was improperly received. However, indemnification for an adverse judgment in a suit by the corporation or in its right, or for a judgment of liability on the basis that a personal benefit was improperly received, is limited to expenses. The MGCL permits a corporation to advance reasonable expenses to a director or officer upon the corporation's receipt of the following:

•

a written affirmation by the director or officer of his or her good faith belief that he or she has met the standard of conduct necessary for indemnification by the corporation; and



•

a written undertaking by him or her, or on his or her behalf, to repay the amount paid or reimbursed by the corporation if it is ultimately determined that this standard of conduct was not met.

        Our declaration of trust authorizes us, and our bylaws require us, to the maximum extent permitted by Maryland law, to indemnify, without requiring a preliminary determination of ultimate entitlement to indemnification, (1) any present or former Trustee or officer of us or (2) any individual who, while a trustee or officer of us and, at our request, serves or has served as a trustee, director, officer or partner of another REIT, corporation, partnership, joint venture, trust, employee benefit plan or other enterprise and who is made or threatened to be made a party to a proceeding by reason of his or her service in that capacity and to pay or reimburse their reasonable expenses in advance of final disposition of the proceeding. Our bylaws also permit us to indemnify and advance expenses to any person who served any predecessor of ours in the capacities described above and any present or former shareholder, employee or agent of us or any such predecessor. Except with respect to proceedings to enforce rights to indemnification, we are required to indemnify a Trustee or officer as described in this paragraph in connection with a proceeding initiated by him or her against us only if such proceeding was authorized by our Board of Trustees.

        We have also entered into indemnification agreements with our Trustees and officers providing for procedures for indemnification by us to the maximum extent permitted by Maryland law and advancements by us of certain expenses and costs relating to claims, suits or proceedings arising from their service to us. We may also maintain directors' and officers' liability insurance for our Trustees and officers.

        Insofar as indemnification for liabilities arising under the Securities Act may be permitted to our Trustees, officers or persons controlling us pursuant to the foregoing provisions of Maryland law and our declaration of trust, we have been informed that in the opinion of the Securities and Exchange Commission, or the SEC, such indemnification is against public policy as expressed in the Securities Act and therefore is unenforceable. Reference is made to our declaration of trust, as amended, filed as Exhibit 3.1 to our Registration Statement on Form S-4 on October 17, 2014, and our bylaws, filed as Exhibit 3.1 to our Current Report on Form 8-K dated September 7, 2016. Reference is also made to our indemnification agreements with our Trustees and officers, a form of which is filed as Exhibit 10.2 to our Quarterly Report on Form 10-Q for the quarter ended March 30, 2018.

        Any underwriting agreement (Exhibit 1.1) that may be filed by amendment or incorporated by reference may contain provisions for indemnification by the underwriters of our officers, trustees and controlling persons.

II-2

---

Table of Contents

Item 16.    Exhibits

Item 17.    Undertakings

        The undersigned registrant hereby undertakes:

        (1)   To file, during any period in which offers or sales are being made, a post-effective amendment to this registration statement:

          (i)  To include any prospectus required by Section 10(a)(3) of the Securities Act of 1933;

         (ii)  To reflect in the prospectus any facts or events arising after the effective date of the registration statement (or the most recent post-effective amendment thereof) which, individually or in the aggregate, represent a fundamental change in the information set forth in the registration statement. Notwithstanding the foregoing, any increase or decrease in volume of securities offered (if the total dollar value of securities offered would not exceed that which was registered) and any deviation from the low or high end of the estimated maximum offering range may be reflected in the form of prospectus filed with the Commission pursuant to Rule 424(b) if, in the aggregate, the changes in volume and price represent no more than a 20 percent change in the maximum aggregate offering price set forth in the "Calculation of Registration Fee" table in the effective registration statement;

        (iii)  To include any material information with respect to the plan of distribution not previously disclosed in the registration statement or any material change to such information in the registration statement;

provided, however, that paragraphs (i), (ii) and (iii) of this section do not apply if the information required to be included in a post-effective amendment by those paragraphs is contained in reports filed

II-3

---

Table of Contents

with or furnished to the Commission by the registrant pursuant to Section 13 or Section 15(d) of the Securities Exchange Act of 1934 that are incorporated by reference in the registration statement, or is contained in a form of prospectus filed pursuant to Rule 424(b) that is part of the registration statement.

        (2)   That, for the purpose of determining any liability under the Securities Act of 1933, each such post-effective amendment shall be deemed to be a new registration statement relating to the securities offered therein, and the offering of such securities at that time shall be deemed to be the initial bona fide offering thereof.

        (3)   To remove from registration by means of a post-effective amendment any of the securities being registered which remain unsold at the termination of the offering.

        (4)   That, for the purpose of determining liability under the Securities Act of 1933 to any purchaser:

          (i)  Each prospectus filed by the registrant pursuant to Rule 424(b)(3) shall be deemed to be part of the registration statement as of the date the filed prospectus was deemed part of and included in the registration statement; and

         (ii)  Each prospectus required to be filed pursuant to Rule 424(b)(2), (b)(5), or (b)(7) as part of a registration statement in reliance on Rule 430B relating to an offering made pursuant to Rule 415(a)(1)(i), (vii), or (x) for the purpose of providing the information required by Section 10(a) of the Securities Act of 1933 shall be deemed to be part of and included in the registration statement as of the earlier of the date such form of prospectus is first used after effectiveness or the date of the first contract of sale of securities in the offering described in the prospectus. As provided in Rule 430B, for liability purposes of the issuer and any person that is at that date an underwriter, such date shall be deemed to be a new effective date of the registration statement relating to the securities in the registration statement to which that prospectus relates, and the offering of such securities at that time shall be deemed to be the initial bona fide offering thereof. Provided, however, that no statement made in a registration statement or prospectus that is part of the registration statement or made in a document incorporated or deemed incorporated by reference into the registration statement or prospectus that is part of the registration statement will, as to a purchaser with a time of contract of sale prior to such effective date, supersede or modify any statement that was made in the registration statement or prospectus that was part of the registration statement or made in any such document immediately prior to such effective date.

        (5)   That, for the purpose of determining liability of the registrant under the Securities Act of 1933 to any purchaser in the initial distribution of the securities:

        The undersigned registrant undertakes that in a primary offering of securities of the undersigned registrant pursuant to this registration statement, regardless of the underwriting method used to sell the securities to the purchaser, if the securities are offered or sold to such purchaser by means of any of the following communications, the undersigned registrant will be a seller to the purchaser and will be considered to offer or sell such securities to such purchaser:

          (i)  Any preliminary prospectus or prospectus of the undersigned registrant relating to the offering required to be filed pursuant to Rule 424;

         (ii)  Any free writing prospectus relating to the offering prepared by or on behalf of the undersigned registrant or used or referred to by the undersigned registrant;

        (iii)  The portion of any other free writing prospectus relating to the offering containing material information about the undersigned registrant or its securities provided by or on behalf of the undersigned registrant; and

II-4

---

Table of Contents

        (iv)  Any other communication that is an offer in the offering made by the undersigned registrant to the purchaser.

        (6)   That, for purposes of determining any liability under the Securities Act of 1933, each filing of the registrant's annual report pursuant to Section 13(a) or Section 15(d) of the Securities Exchange Act of 1934 (and, where applicable, each filing of an employee benefit plan's annual report pursuant to Section 15(d) of the Securities Exchange Act of 1934) that is incorporated by reference in the registration statement shall be deemed to be a new registration statement relating to the securities offered therein, and the offering of such securities at that time shall be deemed to be the initial bona fide offering thereof.

        (7)   Insofar as indemnification for liabilities arising under the Securities Act of 1933 may be permitted to trustees, directors, officers and controlling persons of the registrant pursuant to the foregoing provisions, or otherwise, the registrant has been advised that in the opinion of the Securities and Exchange Commission such indemnification is against public policy as expressed in the Securities Act of 1933 and is, therefore, unenforceable. In the event that a claim for indemnification against such liabilities (other than the payment by the registrant of expenses incurred or paid by a trustee, director, officer or controlling person of the registrant in the successful defense of any action, suit or proceeding) is asserted by such trustee, director, officer or controlling person in connection with the securities being registered, the registrant will, unless in the opinion of its counsel the matter has been settled by controlling precedent, submit to a court of appropriate jurisdiction the question whether such indemnification by it is against public policy as expressed in the Securities Act of 1933 and will be governed by the final adjudication of such issue.

II-5

---

Table of Contents

EXHIBIT INDEX

II-6

---

Table of Contents

SIGNATURES

        Pursuant to the requirements of the Securities Act of 1933, the registrant certifies that it has reasonable grounds to believe that it meets all of the requirements for filing on Form S-3 and has duly caused this registration statement to be signed on its behalf by the undersigned, thereunto duly authorized, in the City of Newton, Commonwealth of Massachusetts, on October 2, 2018.

POWER OF ATTORNEY

        Pursuant to the requirements of the Securities Act of 1933, this registration statement on Form S-3 has been signed below by the following persons in the capacities and on the dates indicated; and each of the undersigned officers and trustees of Select Income REIT, hereby severally constitutes and appoints each of David M. Blackman and John C. Popeo to sign for him or her, and in his or her name in the capacity indicated below, this registration statement for the purpose of registering such securities under the Securities Act of 1933, and any and all amendments thereto, hereby ratifying and confirming their signatures as they may be signed by their attorneys to this registration statement and any and all amendments thereto.

---