
2251 Corporate Park Drive
Herndon, VA 20171
NOTICE OF ANNUAL MEETING OF STOCKHOLDERS
TO BE HELD MAY 21, 2021
The 2021 Annual Meeting of Stockholders (the Annual Meeting) of ManTech International Corporation, a Delaware corporation (the Company), will be held at 2251 Corporate Park Drive, Herndon, VA 20171, on Friday, May 21, 2021, at 11:00 am (EDT), for the following purposes, as more fully described in the proxy statement accompanying this notice:
| 1. | To elect eight (8) persons as directors of the Company, each to serve until the 2022 Annual Meeting of Stockholders, or until their respective successors shall have been duly elected and qualified; |
| 2. | To ratify the appointment of Deloitte & Touche LLP to serve as the Company’s independent registered public accounting firm for the fiscal year ending December 31, 2021; and |
| 3. | To transact such other business as may properly come before the Annual Meeting or any adjournments or postponements thereof. |
Stockholders of record at the close of business on March 26, 2021 are entitled to vote at the Annual Meeting. A complete list of stockholders eligible to vote at the Annual Meeting will be available for examination by our stockholders during the ten days prior to the Annual Meeting, between the hours of 9:00 am and 5:00 pm (EDT), at the Company’s offices, located at 2251 Corporate Park Drive, Herndon, VA 20171.
We invite you to attend the Annual Meeting in person. Whether or not you expect to attend the Annual Meeting, your vote is important. To assure your representation at the Annual Meeting, please sign and date the enclosed proxy card, and return it promptly in the accompanying reply envelope, which requires no additional postage. Should you receive more than one proxy because your shares are registered in different names and addresses, each proxy should be signed and returned to vote all your shares.
Although we intend to hold the Annual Meeting in person, we are sensitive to the public health and travel concerns our stockholders may have and recommendations that public health officials may issue in light of the evolving coronavirus (COVID-19) situation. As a result, we may impose additional procedures or limitations on Annual Meeting attendees, or we may decide to hold the Annual Meeting at a different location or by means of remote communication. We plan to announce any such updates on our proxy website (https://investor.mantech.com/annual-meeting), and we encourage you to check this website prior to the Annual Meeting if you plan to attend.
The proxy statement and form of proxy are being mailed on or about April 16, 2021.
By Order of the Board of Directors

Kevin M. Phillips
Chairman of the Board, CEO and President
Herndon, Virginia
April 16, 2021
Important Notice Regarding Availability of Proxy Materials for ManTech’s
Annual Meeting of Stockholders to be Held on May 21, 2021:
The Proxy Statement, our Proxy Card and our Annual Report to Stockholders are available at
https://investor.mantech.com/annual-meeting