DLH Holdings Corp

We are furnishing proxy materials to our shareholders primarily via the Internet, instead of mailing printed copies of those materials to each shareholder. On or about January 29, 2024, we mailed to our shareholders (other than those who previously requested electronic delivery) a Notice of Internet Availability containing instructions on how to access our proxy materials, including our proxy statement and our annual report. The Notice of Internet Availability also instructs our shareholders on how to access their proxy card to vote through the Internet or by smartphone or tablet. This process is designed to expedite shareholders’ receipt of proxy materials, lower the cost of the annual meeting, and help conserve natural resources. However, if a shareholder would prefer to receive printed proxy materials, the shareholder may follow the instructions included in the Notice of Internet Availability. If a shareholder has previously elected to

{N0366335 } 1 receive our proxy materials electronically, that shareholder will continue to receive these materials via e-mail unless he or she elects otherwise.

Important Notice Regarding the Availability of Proxy Materials for the Annual Meeting of Shareholders on March 14, 2024. The Proxy Statement and our 2023 Annual Report to Shareholders are available at:

https://www.cstproxy.com/dlhcorp/2024