Change in Control Protection Agreement

Exhibit 10.2

Change in Control

Protection Agreement

This CHANGE IN CONTROL PROTECTION AGREEMENT is dated June 3, 2009, by and between ManTech International Corporation, a Delaware corporation (the “ Company ”), and Lawrence B. Prior III (the “ Executive ”).

PURPOSE

In order to induce the Executive to remain in the employment of the Company, particularly in the event of the threat or occurrence of a Change in Control (as hereafter defined), the Company desires to enter into this Agreement to provide the Executive with certain benefits in the event the Executive’s employment is terminated as a result of, or in connection with, a Change in Control.

NOW, THEREFORE, in consideration of the respective agreements of the parties contained herein, it is agreed as follows:

SECTION 1. Definitions

For purposes of this Agreement, the following terms have the meanings set forth below:

“Accrued Compensation” means an amount which includes all amounts earned or accrued by the Executive through and including the Termination Date but not paid to the Executive on or prior to such date, including (a) all base salary, (b) all vacation pay and (c) all bonuses and incentive compensation, paid in the case of (a) promptly after the Termination Date and in the case of (c) in accordance with the terms of the applicable plans or programs.

“Base Salary Amount” means the Executive’s annual base salary at the rate in effect on the Termination Date.

“Board” means the Board of Directors of the Company.

“Bonus Amount” means the target Annual Cash Bonus (as defined in the Employment Agreement) of the Executive for the fiscal year in which the Termination Date occurs, but not less than 120 percent of Base Salary Amount. Bonus Amount includes only the annual cash bonus and does not include any restricted stock awards, options or other long-term incentive compensation that may have been awarded to the Executive.

“Cause” shall have the same meaning as in the Employment Agreement.

“Change in Control” of the Company means, and shall be deemed to have occurred upon, any of the following events:

(a) The acquisition by any Person of beneficial ownership (as defined in Rule 13d-3 of the General Rules and Regulations under the Securities Exchange Act) of fifty percent (50%) or more of the outstanding voting power of the Company’s stock; provided, however, that the following acquisitions shall not constitute a Change in Control for purposes of this subparagraph (a): (i) any acquisition by the Company or any of its Subsidiaries; (ii) any acquisition by any employee benefit plan (or related trust) sponsored or maintained by the Company or any of its Subsidiaries; or (iii) acquisitions complying with the terms of paragraph (c) below.

(b) Individuals who, as of the date of this Agreement, constitute the Board (the “ Incumbent Board ”) cease for any reason to constitute at least a majority of the Board; provided, however, that any individual who becomes a director of the Company subsequent to the date of this Agreement and whose election, or whose nomination for election by the Company’s stockholders, to the Board was either (i) approved by a vote of at least a majority of the directors then comprising the Incumbent Board or (ii) recommended by a nominating committee comprised entirely of directors who are then Incumbent Board members, shall be considered as though such individual were a member of the Incumbent Board, but excluding, for this purpose, any such individual whose initial assumption of office occurs as a result of either an actual or threatened election contest (as such terms are used in Rule 14a-11 of Regulation 14A promulgated under the Securities Exchange Act), other actual or threatened solicitation of proxies or consents or an actual or threatened tender offer; or

(c) Consummation of a reorganization, merger, or consolidation or sale or other disposition of all or substantially all of the assets of the Company (a “ Business Combination ”), in each case unless following such Business Combination, (i) all or substantially all of the Persons who were the Beneficial Owners, respectively, of the outstanding shares and outstanding voting securities immediately prior to such Business Combination own, directly or indirectly, more than fifty percent (50%) of the combined voting power of the then outstanding voting securities entitled to vote generally in the election of directors of the Company, as the case may be, of the entity resulting from the Business Combination (including, without limitation, an entity which as a result of such transaction owns the Company or all or substantially all of the Company’s assets either directly or through one or more subsidiaries) in substantially the same proportions as their ownership, immediately prior to such Business Combination, of the outstanding voting securities (provided, however, that for purposes of this clause (i) any shares of common stock or voting securities of such resulting entity received by such Beneficial Owners in such Business Combination other than as the result of such Beneficial Owners’ ownership of outstanding shares or outstanding voting securities immediately prior to such Business Combination shall not be considered to be owned by such Beneficial Owners for the purposes of calculating their percentage of ownership of the outstanding common stock and voting power of the resulting entity); and (ii) no Person (excluding any entity resulting from such Business Combination or any employee benefit plan (or related trust) of the Company or such entity resulting from the Business Combination) beneficially owns, directly or indirectly, fifty percent (50%) or more of the combined voting power of the then outstanding voting securities of such entity resulting from the Business Combination unless such Person owned fifty percent (50%) or more of the outstanding shares or outstanding voting securities immediately prior to the Business Combination.

(d) Approval by the Company’s stockholders of a complete liquidation or dissolution of the Company.

“Code” means the Internal Revenue Code of 1986, as amended.

“Employment Agreement” means the Employment Agreement dated the date hereof between ManTech and the Executive.

“Disability” shall have the same meaning as under the Employment Agreement.

“Full Release” shall have the same meaning as “Release” under the Employment Agreement.

“Good Reason” shall have the same meaning as under the Employment Agreement, provided that the permitted reduction of base salary pursuant to the parenthetical phrase in Section 5.1(b)(b) of the Employment Agreement shall not apply.

“ Pro Rata Bonus ” shall mean the annual bonus based on actual results for the year of termination and the relative portion of the year during which the Executive provided services, paid when said bonus would have been paid if the Executive continued employment.

“Subsidiary” means any corporation with respect to which another specified corporation has the power under ordinary circumstances to vote or direct the voting of sufficient securities to elect a majority of the directors.

“Successor” means a corporation or other entity acquiring all or substantially all the assets and business of the Company, whether by operation of law, by assignment or otherwise.

“Termination Date” means (a) in the case of the Executive’s death, the Executive’s date of death, and (b) in all other cases, the final date of Executive’s employment with the Company. Notwithstanding anything to the contrary herein, an Executive’s employment shall not be considered to have terminated unless the executive has experienced a “separation from service,” as defined in Code Section 409A and the regulations there under.

SECTION 2. Term of Agreement

The term of this Agreement (the “ Term ”) will commence on July 3, 2009, and will continue in effect for a period of two (2) years; provided however that after such two (2) year period, and on each one (1) year anniversary of such date thereafter, the Term shall automatically be extended for an additional one (1) year, unless not later than ninety (90) days prior to the end of one of the periods, either the Company or the Executive shall have given notice to the other party not to extend the Term. Notwithstanding the foregoing, and subject to Section 4.2, the Term shall be deemed to have immediately expired without any further action, and this Agreement will immediately terminate and be of no further effect if, prior to a Change in Control, the Executive’s employment is terminated for any reason. Additionally, in the event that a Change in Control occurs during the Term, then the Term shall automatically extend for a period of up to two additional years, if necessary, to accommodate the two-year post-Change in Control period specified in Section 4.1 below.

SECTION 3. Acceleration of Options upon Change in Control

If a Change in Control occurs during the Term of this Agreement, then, all unvested stock awards then held by Executive shall accelerate and become immediately vested.

SECTION 4. Termination of Employment after Change in Control

4.1 If the Executive’s employment with the Company is terminated within two (2) years following a Change in Control that occurs during the Term (and following the procedures in the Employment Agreement), the Executive will be entitled to the following compensation and benefits:

(a) If the Executive’s employment with the Company is terminated (i) by th