Performance-Based Restricted Stock Unit Award Agreement with Matthew A. Tait granted under the Management Incentive Plan

Performance-Based Restricted Stock Unit Grant. The Company hereby grants to the recipient of the award (Grantee), subject to the terms and conditions of this Agreement and the Plan, a copy of which the Grantee acknowledges having received, an Award in the form of performance-based Restricted Stock Units (RSUs). The RSUs are notional units (not actual Shares), representing an unfunded, unsecured right to receive shares in the future based on the level of achievement of the performance criteria set forth in Appendix A over a two-year performance period commencing January 1, 2019 and ending December 31, 2020 (Performance Period). The target number of RSUs awarded is 17,400 RSUs (Target Award). The actual number of RSUs that will be earned will be determined in accordance with Appendix A, and may range from 0% to 150% of the Target Award.

Continued Employment Requirement. To earn the RSUs, in addition to satisfying the applicable performance criteria set forth in Appendix A, Grantee must remain employed through the last day of the Performance Period. Except as provided in Section 3 of this Agreement, if Grantee’s employment terminates for any reason before the last day of the Performance Period, the RSUs shall immediately and automatically be forfeited as of the date of termination, and Grantee shall have no further rights with respect to this Award. Subject to Section 15 of this Agreement, the Committee shall determine in its sole discretion whether and when a termination of employment occurs and such determination shall be final and binding.

Death or Disability. If, before the last day of the Performance Period, the Grantee’s employment terminates due to the Grantee’s death or if the Grantee’s employment is terminated by the Company due to the Grantee’s Disability, the Target Award shall become vested as of the date of termination. As soon as practicable (and in all events with 60 days) following the date of such termination of employment, the Company shall issue to the Grantee (or the Grantee’s estate, heir or beneficiary) one Share for each vested Restricted Stock Unit. For purposes of the Award, the Grantee shall be deemed to have a “Disability” if, in the determination of the Committee (or its designee), the Grantee is unable to engage in any substantial gainful activity by reason of any medically determinable physical or mental impairment that can be expected to result in death or can be expected to last for a continuous period of not less than twelve months.

Issuance of Shares. Except as provided in Section 3 of this Agreement, to the extent the Committee (or its designee) determines in accordance with Appendix A that RSUs have been earned, the Company shall issue to the Grantee one Share for each Restricted Stock Unit that is earned, with such issuance occurring between January 1, 2021 and March 15, 2021, as soon as practicable after the Committee or its designee makes its determination.

Tax Withholding. In accordance with Section XIII of the Plan, the Company shall have the power and right to deduct or withhold, or require the Grantee to remit to the Company, an amount sufficient to satisfy any federal, state, local and other taxes (including the Grantee’s payroll tax obligations) required by law to be withheld with respect to this Award. The Grantee may be required to pay to the Company in cash or cash equivalents, either prior to or concurrent with the delivery of Shares in respect of any earned RSUs, the amount required by law to be withheld by the Company. Unless otherwise directed by the Grantee, the Company (or an Affiliate) shall withhold from the number of Shares to be issued in respect of any earned RSUs such number of Shares having an aggregate fair market value equal to minimum amount of the any federal, state, local and other taxes (including the Grantee’s payroll tax obligations) required by law to be withheld by the Company.

Restrictions on Transfer. The RSUs, this Award, and any right to receive Shares pursuant to this Award, may not be sold, assigned, transferred, encumbered, hypothecated or pledged by the Grantee.

Limitation of Rights. The Grantee shall not have any privileges of a stockholder of the Company with respect to the RSUs (including, for the sake of clarity, any voting rights, or any right to dividends or dividend equivalents) unless and until actual Shares are issued pursuant to Section 3 or Section 4 of this Agreement, above. Nothing in this Agreement shall confer upon the Grantee any right to continue as an employee of the Company or an affiliate or to interfere in any way with any right of the Company to terminate the Grantee’s employment at any time.

Changes in Capitalization. The RSUs shall be subject to the provisions of Sections 11.1 and 11.2 of the Plan relating to adjustments for changes in capital structure.

Notices. All notices and other communications required or permitted to be given hereunder shall be in writing and shall be deemed to have been duly given (a) if personally delivered, upon delivery or refusal of delivery, (b) if mailed by registered or certified United States mail, return receipt requested, postage prepaid, upon delivery or refusal of delivery, (c) if sent by a nationally recognized overnight delivery service, upon delivery or refusal of delivery, or (d) if sent by facsimile or electronic mail, upon confirmation of delivery. All notices, consents, waivers or other communications required or permitted to be given hereunder shall be addressed as follows):

If to the Company to:

If to the Grantee, to the address of the Grantee in the records of the Company.

Construction. This Agreement and RSUs hereunder are granted by the Company pursuant to the Plan and are in all respects subject to the terms and conditions of the Plan. The Grantee hereby acknowledges that a copy of the Plan has been delivered to the Grantee and accepts the RSUs hereunder subject to all terms and provisions of the Plan, which are incorporated herein by reference. The construction of and decisions under the Plan and this Agreement are vested in the Committee (or its designee), whose determinations shall be final, conclusive and binding upon the Grantee.

Governing Law. This Agreement shall be governed by, and construed in accordance with, the laws of the State of Delaware, excluding the choice of law rules thereof.

Counterparts. This Agreement may be executed in counterparts, each of which shall be deemed to be an original but all of which together shall constitute one and the same instrument.

Entire Agreement. This Agreement and the Plan constitute the entire agreement between the parties with respect to the subject matter hereof and thereof.

Clawback Policy. This Award, and any amounts earned hereunder shall be subject to the Company’s clawback policy, as may be amended or superseded from time to time.

Section 409A. This Award is intended to be exempt from Section 409A of the Internal Revenue Code of 1986, as amended, the regulations issued thereunder or any exception thereto (Section 409A) under the short-term deferral exception in Treas. Reg. §1.409A-l(b)(4). To the extent applicable, the provisions of this Agreement shall be interpreted and construed in a manner intended to comply with Section 409A. To the extent all or any portion of the Award is determined to constitute deferred compensation for purposes of Section 409A, and settlement of the Award (or the portion thereof that is determined to constitute deferred compensation) is triggered by a termination of the Grantee’s employment, the Grantee shall not be deemed to have terminated employment unless and until the Grantee has experienced a “separation from service,” as that term is used in Section 409A. The Company makes no representation that this Award will comply with Section 409A and makes no undertaking to prevent Section 409A from applying to this Award or to mitigate its effects on this Award.

The number of Restricted Stock Units earned will be determined based on the extent to which the Revenue and EBIT goals (for each of ManTech and MSS) described below have been achieved over the two-year Performance Period.

For purposes of this Award, the compounded annual growth rate (CAGR) of a performance measurement shall mean the year-over-year growth rate of that performance measure over the two-year Performance Period. CAGR shall be calculated as follows:

For purposes of this Award, the Target Performance Score is based on the sum of goals for ManTech Revenue CAGR, ManTech EBIT CAGR, MSS Revenue CAGR and MSS EBIT CAGR, such that the Combined CAGR Target Performance Score is 68.3%.

The Actual Performance Score is the sum of the calculation of four above-referenced CAGR measures.

The Final Performance Score is the result of the Actual Performance Score divided by the Target Performance Score.

Subject to Section 9 of this Appendix below, the number of Restricted Stock Units earned shall be determined pursuant to the following schedule:

For purposes of this Award, the term “Revenue” means the total revenue from all sources determined in accordance with GAAP (and with respect to ManTech Revenue, as reported in the Company’s Form 10-K for the corresponding fiscal year) for the applicable entity, as may be adjusted in accordance with Section 9 of this Appendix A, below.

For purposes of this Award, the term EBIT means earnings before interest and taxes determined in accordance with GAAP (and with respect to ManTech EBIT, as reported in the Company’s Form 10-K for the corresponding fiscal year) for the applicable entity, as may be adjusted in accordance with Section 9 of this Appendix 9, below.

All calculations with respect to the Award shall be made by the Committee (or its designee) in the Committee’s sole discretion, and such calculations and resulting determinations shall be final and binding. Without limiting the foregoing, the performance measures may be adjusted to exclude the cumulative effect of changes in accounting policies adopted by the Company during the Performance Period or to take into account unexpected, extraordinary or other events and may, in the discretion of the Committee (or its designee) otherwise adjust the amounts that would otherwise be earned by the Grantee pursuant to this Appendix A.