PSTRQ PostRock Energy Corporation (CE)

PROXY STATEMENT

FOR

2013 ANNUAL MEETING OF STOCKHOLDERS

This proxy statement is furnished in connection with the solicitation of proxies by our board of directors for use at the 2013 Annual Meeting of Stockholders of PostRock Energy Corporation to be held on May 7, 2013 or at any adjournment or postponement thereof, at the time and place and for the purposes specified in the accompanying notice of annual meeting.

We have elected to provide access to our proxy materials over the Internet and are sending a Notice of Internet Availability of Proxy Materials (the “Notice”) to our stockholders of record. All stockholders will have the ability to access the proxy materials. Instructions on how to access the proxy materials over the Internet or to request a printed copy may be found on the Notice.

All properly delivered proxies pursuant to this solicitation, and not later revoked, will be voted at the annual meeting in accordance with the instructions given in the proxy. When voting regarding the election of directors, stockholders may vote in favor of all nominees, withhold their votes as to all nominees or withhold their votes as to specific nominees. When voting regarding the approval of the amendment to our 2010 Long-Term Incentive Plan, the approval of our deferred compensation plan, the ratification of the appointment of our registered public accounting firm and the advisory vote on executive compensation, stockholders may vote for or against the proposal or may abstain from voting. When voting on the frequency of future advisory votes on executive compensation, stockholders may select a frequency of every one, two or three years, or abstain. Stockholders should vote their shares on the proxy card we have provided. If no choice is indicated, proxies that are signed and returned will be voted as recommended by our board of directors.

All shares of our common stock represented by properly delivered and unrevoked proxies will be voted if such proxies are received in time for the meeting.

QUORUM, VOTE REQUIRED AND REVOCATION OF PROXIES

The board of directors has established March 15, 2013 as the record date for the determination of stockholders entitled to notice of and to vote at the annual meeting. As of the record date, 23,820,513 shares of common stock and 26,509,549 one one-hundredths of a share, or “fractional share,” of Series B Voting Preferred Stock were outstanding. Each share of common stock and each fractional share of Series B preferred stock is entitled to one vote upon each matter to be voted on at the meeting. The holders of Series B preferred stock are entitled to vote in the election of directors and on all other matters submitted to a vote of the holders of our common stock, with the holders of Series B preferred stock and the holders of common stock voting together as a single class. With respect to the votes applicable to the Series B preferred stock, the holders of the Series B preferred stock and their affiliates are currently limited to 45% of the votes applicable to all outstanding voting stock. Those holders and their affiliates also are entitled to vote any common stock held by them. Accordingly, based on the ownership of the holders of the Series B preferred stock and their affiliates as of the record date with respect to the annual meeting, those holders and their affiliates are entitled to cast at the annual meeting approximately 67.7% of the votes entitled to be cast by all voting stock and therefore control the outcome of the voting on each matter to be presented at the meeting. The presence, in person or by proxy, of the holders of shares of capital stock entitled to cast a majority of the votes that could be cast at the annual meeting by the holders of all outstanding shares of capital stock entitled to vote at the meeting is necessary to constitute a quorum.

The seven nominees for director who receive the greatest number of votes cast at the meeting will be elected as directors. Cumulative voting is not permitted in the election of directors. The amendment of our 2010 Long-Term Incentive Plan, the approval of our deferred compensation plan, the ratification of the appointment of our independent registered public accounting firm and the advisory vote on executive compensation are subject to the approval of a majority of the votes cast on the proposal. The alternative (other than abstention) regarding the frequency of future advisory votes on executive compensation that receives the most votes will be deemed the recommendation of the stockholders.

Brokers holding shares of our common stock must vote according to specific instructions they receive from the beneficial owners of those shares. If brokers do not receive specific instructions, brokers may in some cases vote the shares in their discretion. At the annual meeting, brokers may vote only on the ratification of the appointment of our independent registered public accounting firm without instructions from the beneficial owners. Brokers cannot vote on the other matters to be considered at the meeting without those instructions. If you do not instruct your broker how to vote on those matters, your broker will not vote on your behalf.

Abstentions and broker non-votes are counted as present in determining whether the quorum requirement is satisfied. For purposes of determining the outcome of any question as to which the broker has indicated that it does not have discretionary authority to vote, these shares will be treated as not present with respect to that question, even though those shares are considered present for quorum purposes and may be entitled to vote on other questions. Because the seven nominees for director who receive the greatest number of votes cast at the meeting will be elected as directors, abstentions and broker non-votes will not affect the outcome of the voting on the elections. Because the amendment of our 2010 Long-Term Incentive Plan, the approval of our deferred compensation plan, the ratification of the appointment of our independent registered accounting firm and the advisory vote on executive compensation require the approval of a majority of the votes cast, abstentions and broker non-votes will not affect the outcome of the voting on those proposals. With respect to the advisory vote on the frequency of future advisory votes on executive compensation, because the alternative (other than abstention) that receives the most votes will be deemed the recommendation of stockholders, broker non-votes will not affect the outcome of the voting on that proposal.

Any holder of our capital stock has the right to revoke his or her proxy at any time prior to the voting thereof at the annual meeting by (1) filing a written revocation with the Secretary prior to the voting of such proxy, (2) giving a duly executed proxy bearing a later date or (3) attending the annual meeting and voting in person. Attendance by a stockholder at the annual meeting will not itself revoke his or her proxy. If you hold your shares in the name of a bank, broker or other nominee, you should follow the instructions provided by your bank, broker or nominee in revoking your previously granted proxy.

COST AND METHOD OF PROXY SOLICITATION

We will bear the cost of the solicitation of proxies. In addition to solicitation by mail, our directors, officers and employees may solicit proxies from stockholders by telephone or facsimile or in person. We will supply banks, brokers, dealers and other custodian nominees and fiduciaries with proxy materials to enable them to send a copy of such material by mail to each beneficial owner of shares of our common stock that they hold of record and will, upon request, reimburse them for their reasonable expenses in doing so.

ELECTION OF DIRECTORS

(Item 1 on Proxy Card)

The board of directors has nominated the seven people listed below for election as directors, each to serve until the next annual meeting of stockholders or until his successor is elected and qualified. If any of the nominees becomes unavailable for any reason, which is not anticipated, the board of directors in its discretion may designate a substitute nominee. If you have filled out the accompanying proxy card, your vote will be cast for the substitute nominee.

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Explanatory Note

In this proxy statement, unless otherwise indicated or the context otherwise requires:

Nominees for Election

Each of the nominees for director has been approved by the board of directors, upon the recommendation of the Nominating, Corporate Governance, Safety and Environment Committee, for submission to the stockholders. Set forth below is the current principal occupation (which, unless otherwise indicated, has been his principal occupation during the last five years), age and other information for each nominee:

Nathan M. Avery , age 78, became a director of PostRock in September 2010 and is a designee of White Deer Energy L.P. as described below under “Certain Relationships and Related Transactions, and Director Independence — White Deer Investment.” Mr. Avery served as a director of Cameron International Corporation from 1995 until 2009. He was founder, Chairman of the Board and Chief Executive Officer of Galveston-Houston Company, an NYSE company specializing in the manufacturing of products to serve the energy and mining industries, from 1972 to December 2000, when it was sold to Komatsu, Ltd. He has been an active participant in the oil and gas industry since the 1960s and was Chairman of the Board of Directors of Bettis Corporation, an actuator company, until 1996, when Bettis Corporation merged with Daniel Industries, Inc., and was a director and member of the Executive Committee of Daniel Industries until June 1999, when Daniel Industries merged with Emerson Electric Co. Mr. Avery holds a B.S. in Petroleum Engineering from the Colorado School of Mines. The board of directors is nominating Mr. Avery because of his active participation in the oil and gas industry since the 1960s and his strong technical expertise.

Terry W. Carter , age 60, became Interim President and Chief Executive Officer in June 2011 and President and Chief Executive Officer and a director in December 2011. Since February 2008, Mr. Carter has been a principal of a number of private oil and gas ventures. From 2003 through November 2007, Mr. Carter served as President and Chief Executive Officer of Ascent Energy, Inc., a private exploration and production company. In 2001, Mr. Carter became Executive Vice President of Exploration and Production at Range Resources Corporation, an exploration and production company, where he served in that role until 2003. Mr. Carter began his career as a petroleum engineer for ORYX Energy, formerly Sun Exploration and Production. In the course of his more than 20 years with that company, he rose to become Manager of Operations and Development in Dallas. Mr. Carter holds a B.S. in Petroleum Engineering from Tulsa University. The board of directors is nominating Mr. Carter because, in addition to valuing his significant operating experience, the board believes that having his perspective as the Chief Executive Officer of our company enhances the board’s focus on and contribution to our growth and development and is in the best interest of our stockholders.

William H. Damon III , age 60, became a director of PostRock in March 2010 upon completion of the recombination. Mr. Damon joined QRCP as a director in April 2007 and served in that capacity until March 2010. He has over 35 years of professional experience specializing in engineering design and development of power generation projects and consulting services. Since January 2008, he has served as Senior Vice President and National Director of Power Consulting for HDR, Inc., which purchased the engineering-consulting firm, Cummins & Barnard, Inc., which was focused on power generation development and engineering projects for electric utilities, independent power producers, large industrial and institutional clients throughout the United States. Mr. Damon served as the Chief Executive Officer of Cummins &

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Barnard and had been its principal and co-owner from 1990 to January 2008. He currently leads HDR’s project development and strategic consulting business for coal, natural gas and renewable energy projects. He previously worked for Consumers Power Company, Gilbert-Commonwealth, Inc. and Alternative Energy Ventures. He also held board seats on a minerals and wind turbine company, MKBY, and a start-up construction company that was sold to Aker Kvaerner Songer, in which he was also a founding member. Mr. Damon graduated from Michigan State University with a B.S. in Mechanical Engineering and continued graduate studies at both Michigan State University and the University of Michigan. The board of directors is nominating Mr. Damon because of his background and experience in the energy industry, his knowledge of compensation practices and risk management from his management experience at both HDR and Cummins & Barnard and his service and performance as Chair of our Compensation Committee.

Thomas J. Edelman , age 62, became a director of PostRock in September 2010 and is a designee of White Deer Energy L.P. Mr. Edelman is currently a Managing Partner of White Deer Energy, an energy private equity fund formed in 2008. Previously, Mr. Edelman founded Patina Oil & Gas Corporation and served as its Chairman and Chief Executive Officer from its formation in 1996 through its merger with Noble Energy, Inc. in 2005. In 2005, he founded BioFuel Energy Corporation and served as its Chairman until 2008. He co-founded Snyder Oil Corporation and was its President from 1981 through 1997. He served as Chairman and Chief Executive Officer and later as Chairman of Range Resources Corporation from 1988 through 2003. From 1980 to 1981, he was with The First Boston Corporation and, from 1975 through 1980, with Lehman Brothers Kuhn Loeb Incorporated. Mr. Edelman also currently serves as President of Lenox Hill Neighborhood House, a New York based charity, as a Trustee and Chair of the Investment Committee of The Hotchkiss School, a member of the Board of Directors of Georgetown University and a Director of Berenson & Company. Mr. Edelman holds an M.B.A. in Finance from Harvard Business School, graduating as a Baker Scholar, and a B.A. in Political Economy from Princeton University, graduating magna cum laude. The board of directors is, in part, nominating Mr. Edelman because of his expertise in managing publicly traded exploration and production companies.

Duke R. Ligon , age 71, became a director of PostRock in March 2010 upon completion of the recombination. Mr. Ligon served as a director of QMGP from December 2006 to March 2010. Since September 2010, Mr. Ligon has served as our Chairman of the Board. From January 2007 to February 2010, Mr. Ligon was a Legal Strategic Advisor to Love’s Travel Stops & Country Stores, Inc. and the Executive Director of the Love’s Entrepreneurship Center of Oklahoma City University. From February 1997 to January 2007, Mr. Ligon served as the Senior Vice President and General Counsel for Devon Energy Corporation. Mr. Ligon is an attorney and has more than 35 years of legal expertise in corporate securities, litigation, governmental affairs and mergers and acquisitions. Prior to joining Devon in 1997, he practiced law for 12 years and last served as a partner at the law firm of Mayer, Brown & Platt in New York City. In addition, he was Senior Vice President and Managing Director for Investment Banking at Bankers Trust Co. in New York City for 10 years. He is also a member of the board of directors of Vantage Drilling Company, Blueknight Energy Partners, L.P., Panhandle Oil and Gas Inc., Pre-Paid Legal Services, Inc. and SteelPath MLP Funds Trust and previously served on the boards of TransMontaigne Partners L.P. and TEPPCO Partners, L.P. Mr. Ligon received an undergraduate degree in chemistry from Westminster College and a law degree from the University of Texas School of Law. The board of directors is nominating Mr. Ligon because his experience with Devon Energy Corporation and his expertise in corporate securities, litigation, governmental affairs and mergers and acquisitions brings a unique perspective to the board of directors.

J. Philip McCormick , age 71, became a director of PostRock in March 2010 upon completion of the recombination. Mr. McCormick was a director of QEGP from November 2008 until March 2010. Mr. McCormick has 26 years of public accounting experience and was in leadership roles at KMG Main Hurdman and KPMG LLP, serving as a member of the board of each firm. Since 1999, Mr. McCormick has been an independent investor and corporate advisor. He was a director and chairman of the audit committee of NASDAQ-listed Advanced Neuromodulation Systems Inc. from 2003 to 2005 until its sale, and he currently serves as a director and member of the Audit Committee of RENN Global Entrepreneurs Fund, Inc. Mr. McCormick holds a B.B.A. degree in Accounting and a Master of Science from Texas A&I

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University. The board of directors is nominating Mr. McCormick because of his public accounting experience, his experience evaluating financial risks and his performance as Chair of our Audit Committee.

Mark A. Stansberry , age 57, became a director of PostRock in March 2010 upon completion of the recombination. Mr. Stansberry was a director of QEGP from November 2007 until March 2010. Mr. Stansberry currently serves as the Chairman and a director of The GTD Group. He has served as Chairman of The GTD Group since 1998. He has served as Chairman of the Governor’s International Team and Chairman of the Board of Regents of the Regional University System of Oklahoma and has served as Chairman of the State Chamber’s Energy Council in Oklahoma. He also serves on a number of other boards, including Chairman of the Board of Directors of People to People International, and has served as president of the International Society of The Energy Advocates. Mr. Stansberry has testified before the U.S. Senate Energy and Natural Resources Committee and is the author of the book: The Braking Point: America’s Energy Dreams and Global Economic Realities. Mr. Stansberry has a B.A. from Oklahoma Christian University and is a graduate of The Fund for American Studies, Georgetown University and of the Intermediate School of Banking, Oklahoma State University. The board of directors is nominating Mr. Stansberry because of his expertise related to the U.S. energy industry and economics.

Vote Required and Board Recommendation

If a quorum is present at the annual meeting, the seven nominees receiving the greatest number of votes cast will be elected as directors. Your board of directors unanimously recommends a vote “FOR” election of the aforementioned seven director nominees.

Corporate Governance

Board Leadership Structure.     The functions performed by the chief executive officer and non-executive chairman of the board are currently performed by separate individuals. Terry W. Carter, chief executive officer, is responsible for the development of the long-term strategies of the company for board consideration and approval; for the implementation of such strategies; and for all aspects of managing our operations and profitability. Duke R. Ligon, non-executive chairman, focuses his attention on board and committee matters, including setting the board’s agenda with Mr. Carter, and is the principal liaison between the independent directors and Mr. Carter.

Code of Business Conduct and Ethics.     We have adopted a Code of Business Conduct and Ethics, which addresses conflicts of interests, that is applicable to our directors and employees, including our principal executive officer, principal financial officer and principal accounting officer. The Code describes the types of transactions that may be subject to the review, approval or ratification of the Audit Committee or our chief compliance officer. Any waiver of any provision of the Code for a member of our board of directors, an executive officer, or a senior financial or accounting officer must be approved by the board, and any such waiver will be promptly disclosed as required by law or NASDAQ rule.

A copy of our Code of Business Conduct and Ethics is available on our website at www.pstr.com under the heading About Us — Corporate Governance. We intend to post any amendment to or waiver from the Code that applies to executive officers or directors on our website.

Accounting and Auditing Concerns.     The Audit Committee has established procedures to receive, retain and treat complaints regarding accounting, internal accounting controls or auditing matters and to allow for the confidential and anonymous submission by employees of concerns regarding questionable accounting or auditing matters. We also have a confidential hotline by which employees can communicate concerns or complaints regarding these matters.

Stockholder Communication with the Board of Directors.     Stockholders may communicate with the board of directors by submitting their communications in writing, addressed to the board as a whole or, at the election of the stockholder, to one or more specific directors, in care of the Secretary, PostRock Energy Corporation, 210 Park Avenue, Suite 2750, Oklahoma City, Oklahoma 73102.

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Board’s Role in Risk Oversight.     The board of directors is responsible for determining the ultimate direction of our business, determining the principles of our business strategy and policies and promoting our long-term interests. Viewed from this perspective, the board of directors generally oversees risk management, and the chief executive officer and other members of executive management generally manage the material risks that we face. The board of directors focuses on the most significant risks facing our company and our general risk management strategy. In accordance with the charter of the Audit Committee, the Audit Committee periodically inquires of management and the independent auditors about significant risks or exposures facing our company, assesses the steps management has taken or proposes to take to minimize such risks, and reviews compliance with such steps. In addition to the risk oversight exercised by the full board of directors and the Audit Committee, the Compensation Committee reviews the risks, if any, that could arise from our compensation policies and practices.

Organization of the Board of Directors

Overview.     The board of directors is responsible for oversight of our business and affairs. To assist it in carrying out its duties, the board has delegated certain authority to a Nominating, Corporate Governance, Safety and Environment Committee, an Audit Committee and a Compensation Committee. The board also has delegated, and may in the future delegate, certain authority to other committees of the board from time to time. The board of directors held nine meetings in 2012. Each current director attended at least 75% of the total number of meetings of the board of directors and of the committees of the board on which he served that were held during the term of his service on the board and its committees. Directors are expected to attend meetings of the board of directors and meetings of committees on which they serve and to spend as much time and meet as frequently as necessary to properly discharge their responsibilities.

Nominating, Corporate Governance, Safety and Environment Committee.     The Nominating, Corporate Governance, Safety and Environment Committee currently consists of Messrs. Stansberry (Chair), Ligon and Avery. The board of directors has determined that the members of the committee are independent under applicable NASDAQ listing standards. The committee is responsible for (1) identifying individuals qualified to become board members, (2) recommending to the board a slate of director nominees to be elected by the stockholders at the next annual meeting of stockholders and, when appropriate, director appointees to take office between annual meetings, (3) recommending to the board membership on standing board committees, (4) developing and recommending to the board appropriate corporate governance policies, practices and procedures for our company, and (5) reviewing the company’s safety and environmental policies, practices and procedures and making recommendations to the board concerning the same. The committee held four meetings during 2012. The charter of the committee is available on our website at www.pstr.com under the heading About Us — Corporate Governance.

Although the board of directors does not have a formal diversity policy, the Nominating, Corporate Governance, Safety and Environment Committee, when assessing the qualifications of prospective nominees to the board of directors, considers each nominee’s personal and professional integrity, experience, skills, ability and willingness to devote the time and effort necessary to be an effective board member, and commitment to acting in the best interests of our company and stockholders. The Nominating, Corporate Governance, Safety and Environment Committee also gives consideration to the qualifications that the Committee believes must be met by prospective nominees to the board, qualities or skills that the Committee believes are necessary for one or more of our directors to possess and standards for the overall structure, diversity and composition of the board.

The Nominating, Corporate Governance, Safety and Environment Committee will consider director candidates recommended by stockholders. If a stockholder wishes to recommend a director for nomination by the committee, the stockholder should submit the recommendation in writing to the Chairman, Nominating, Corporate Governance, Safety and Environment Committee, in care of the Secretary, PostRock Energy Corporation, 210 Park Avenue, Suite 2750, Oklahoma City, Oklahoma 73102. The recommendation should contain the following information:

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Candidates recommended by stockholders are evaluated on the same basis as candidates recommended by our directors, executive officers, third-party search firms or other sources.

Audit Committee.     The Audit Committee currently consists of Messrs. McCormick (Chair), Avery and Stansberry. The board of directors has determined that the members of the Audit Committee are independent under applicable provisions of the Securities Exchange Act of 1934 and the NASDAQ listing standards. The board of directors also has determined that Mr. McCormick is an audit committee financial expert as defined by applicable SEC rules. The committee’s primary purpose is to oversee our accounting and financial reporting processes and the audits of our financial statements. The Audit Committee has direct responsibility for the appointment, retention, compensation and oversight of our independent registered public accounting firm for the purpose of preparing our annual audit report or performing other audit, review or attest services for us. The committee held eight meetings during 2012. The charter of the committee is available on our website at www.pstr.com under the heading About Us — Corporate Governance.

Compensation Committee.     The Compensation Committee currently consists of Messrs. Damon (Chair), Ligon, and Edelman. The board of directors has determined that the members of the committee are independent under applicable NASDAQ listing standards. The committee’s purpose is, among other things (1) to review and approve the compensation of our executive officers, (2) to oversee and advise the board on the adoption of policies that govern our compensation programs and (3) to administer our 2010 Long-Term Incentive Plan and other equity-based compensation plans. The committee may delegate certain authority to a subcommittee of its members. The committee held five meetings during 2012. The charter of the committee is available on our website at www.pstr.com under the heading About Us — Corporate Governance.