TIER Tier Reit, Inc.

Filed by Cousins Properties Incorporated

pursuant to Rule 425 under the Securities Act of 1933

and deemed filed pursuant to Rule 14a-12

under the Securities Exchange Act of 1934

Subject Company: TIER REIT, Inc.

Commission File No.: 001-37512

Date: March 25, 2019

On March 25, 2019, the following news article was published regarding the pending acquisition of TIER REIT, Inc. by Cousins Properties Incorporated.

Atlanta’s Cousins Properties to merge with Sun Belt competitor

By J. Scott Trubey, The Atlanta Journal-Constitution

Cousins Properties, one of Atlanta’s best-known developers and largest office landlords, on Monday announced it will merge with a Dallas-based rival in an all-stock deal set to create a nearly $6 billion real estate company by stock value.

“The combined company will retain the Cousins name and be based in Atlanta. The merger with TIER REIT will give Cousins some 21 million square feet of top-end or Class A office space across the Sun Belt, including landmark towers in Atlanta, Austin, Charlotte, Dallas and Phoenix.

In an interview, Cousins President and CEO Colin Connolly, who will lead the combined company, said the deal bolsters Cousins’ position in Austin and gives the company a foothold in two of Dallas’ most popular office submarkets. It also increases Cousins’ development pipeline, though Connolly noted that the current development cycle is maturing, and new office development will be based on market demand.

“Clearly, we’re in a mature part of the economic cycle,” Connolly said. “That being said, as we look at our Sun Belt office markets, they continue to perform very well. Demand remains robust and I’d say in particular the Sun Belt continues to outperform as the migration continues to take hold where we see companies moving from the Northeast to the Southeast.”

Cousins’ Atlanta holdings include the Terminus office towers and 3344 Peachtree in Buckhead, as well as the Promenade in Midtown. Cousins also developed the NCR headquarters and recently started construction of the new Norfolk Southern headquarters in Midtown.

The deal values TIER at about $2.4 billion. Cousins shareholders will control about 72 percent of the combined company.

Once the deal is completed, which is expected in the third quarter, about 31 percent of Cousins’ portfolio will be in Atlanta, Austin will rank second at 24 percent and Charlotte will be third at 19 percent. TIER’s holdings in Houston and New Jersey are likely to be sold.

TIER recently announced plans to partner with Atlanta-based Regent Partners and Batson-Cook Development Company to build a new 44-story office and condo tower in Buckhead overlooking Ga. 400.

Cousins, founded by Tom Cousins in 1958, is one of Atlanta’s storied real estate firms. It started in residential development, but Cousins expanded into commercial, industrial, retail and apartments.

The company is now primarily focused on office developments in fast-growing Sun Belt metros.

The company has developed or been a partner in many well-known Atlanta landmarks, including CNN Center, 191 Peachtree, Bank of America Plaza, the Wildwood office park in Cobb and North Point Mall.

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Cautionary Statement Regarding Forward-Looking Information

In addition to historical information, this communication contains forward-looking statements within the meaning of the Private Securities Litigation Reform Act of 1995. These forward-looking statements, which are based on current expectations, estimates and projections about the industry and markets in which Cousins and Tier operate and beliefs of and assumptions made by Cousins management and TIER management, involve uncertainties that could significantly affect the financial or operating results of Cousins, TIER or the combined company. Words such as “expects,” “anticipates,” “intends,” “plans,” “believes,” “seeks,” “estimates,” “will,” “should,” “may,” “projects,” “could,” “estimates” or variations of such words and other similar expressions are intended to identify such forward-looking statements, which generally are not historical in nature, but not all forward-looking statements include such identifying words. Such forward-looking statements include, but are not limited to, projections of earnings, statements of plans for future operations or expected revenues, statements about the benefits of the transaction involving Cousins and TIER, including future financial and operating results, the combined company’s plans, objectives, expectations and intentions. All statements that address operating performance, events or developments that we expect or anticipate will occur in the future — including statements relating to creating value for stockholders, benefits of the proposed transaction to stockholders, employees, tenants and other constituents of the combined company, rent and occupancy growth, development activity and changes in sales or contribution volume of developed properties, integrating our companies, cost savings, the expected timetable for completing the proposed transaction, general conditions in the geographic areas where we operate and the availability of capital in existing or new property funds — are forward-looking statements. These statements are not guarantees of future performance and involve certain risks, uncertainties and assumptions that are difficult to predict. Although we believe the expectations reflected in any forward-looking statements are based on reasonable assumptions, we can give no assurance that our expectations will be attained and therefore, actual outcomes and results may differ materially from what is expressed or forecasted in such forward-looking statements. For example, these forward-looking statements could be affected by factors including, without limitation, risks associated with (i) national, international, regional and local economic climates, (ii) changes in financial markets, interest rates and foreign currency exchange rates, (iii) increased or unanticipated competition for our properties, (iv) risks associated with acquisitions, (v) the potential liability for a failure to meet regulatory requirements, including the maintenance of real estate investment trust status, (vi) availability of financing and capital, (vii) changes in demand for developed properties, (viii) risks associated with achieving expected revenue synergies or cost savings, (ix) risks associated with the ability to consummate the transaction and the timing of the closing of the transaction, (x) the ability to successfully integrate our operations and employees following the closing of the transaction, (xi) material changes in the dividend rates on securities or the ability to pay dividends on common shares or other securities, (xii) potential changes to tax

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legislation, (xiii) adverse changes in financial condition of joint venture partner(s) or major tenants, (xiv) risks associated with the acquisition, development, expansion, leasing and management of properties, (xv) the potential impact of announcement of the proposed transaction or consummation of the proposed transaction on relationships, including with tenants, employees and customers; the unfavorable outcome of any legal proceedings that have been or may be instituted against Cousins or TIER, (xvi) significant costs related to uninsured losses, condemnation, or environmental issues, (xvii) the ability to retain key personnel, (xviii) the amount of the costs, fees, expenses and charges related to the proposed transaction and the actual terms of the financings that may be obtained in connection with the proposed transaction, and (xix) those additional risks and factors discussed in reports filed with the SEC by Cousins and TIER from time to time, including those discussed under the heading “Risk Factors” in their respective most recently filed reports on Form 10-K and 10-Q. Except to the extent required by applicable law or regulation, each of Cousins and TIER disclaims any duty to update any forward-looking statements contained in this communication or to otherwise update any of the above-referenced factors.

Important Additional Information and Where to Find It

In connection with the proposed merger, Cousins will file with the Securities and Exchange Commission (the “SEC”) a registration statement on Form S-4 to register the shares of Cousins common stock to be issued in connection with the merger.  The registration statement will include a joint proxy statement/prospectus which will be sent to the stockholders of Cousins and TIER seeking their approval of their respective transaction-related proposals.  INVESTORS AND SECURITY HOLDERS ARE URGED TO READ THE REGISTRATION STATEMENT ON FORM S-4 AND THE RELATED JOINT PROXY STATEMENT/PROSPECTUS, AS WELL AS ANY AMENDMENTS OR SUPPLEMENTS TO THOSE DOCUMENTS AND ANY OTHER RELEVANT DOCUMENTS TO BE FILED WITH THE SEC IN CONNECTION WITH THE PROPOSED MERGER, WHEN THEY BECOME AVAILABLE, BECAUSE THEY WILL CONTAIN IMPORTANT INFORMATION ABOUT COUSINS, TIER AND THE PROPOSED TRANSACTION.

Investors and security holders may obtain copies of these documents free of charge through the website maintained by the SEC at www.sec.gov or from Cousins at its website, www.cousins.com, or from TIER at its website, www.tierreit.com.  Documents filed with the SEC by Cousins will be available free of charge by accessing Cousins’ website at www.cousins.com under the heading Investor Relations, or, alternatively, by directing a request by telephone or mail to Cousins at 3344 Peachtree Road NE, Suite 1800, Atlanta, GA 30326, and documents filed with the SEC by TIER will be available free of charge by accessing TIER’s website at www.tierreit.com under the heading Investor Relations or, alternatively, by directing a request by telephone or mail to TIER at 5950 Sherry Lane, Suite 700, Dallas, Texas 75225.

PARTICIPANTS IN THE SOLICITATION

Cousins and TIER and certain of their respective directors and executive officers and other members of management and employees may be deemed to be participants in the solicitation of proxies from the stockholders of TIER and Cousins in respect of the proposed transaction under the rules of the SEC. Information about TIER’s directors and executive officers is available in TIER’s proxy statement dated April 9, 2018 for its 2018 Annual Meeting of Stockholders, and certain of its Current Reports on Form 8-K. Information about Cousins’ directors and executive officers is available in Cousins’ proxy statement dated March 14, 2019 for its 2019 Annual Meeting of Stockholders, and certain of its Current Reports on Form 8-K. Other information regarding the participants in the proxy solicitation and a description of their direct and indirect interests, by security holdings or otherwise, will be contained in the joint proxy statement/prospectus and other relevant materials to be filed with the SEC regarding the merger when they become available. Investors should read the joint proxy statement/prospectus carefully when it becomes available before making any voting or investment decisions. You may obtain free copies of these documents from TIER or Cousins using the sources indicated above.

NO OFFER OR SOLICITATION

This document shall not constitute an offer to sell or the solicitation of an offer to buy any securities, nor shall there be any sale of securities in any jurisdiction in which such offer, solicitation or sale would be unlawful prior to registration or qualification under the securities laws of any such jurisdiction. No offering of securities shall be made except by means of a prospectus meeting the requirements of Section 10 of the U.S. Securities Act of 1933, as amended.

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