| Under Secretary of Defense for Acquisition and Sustainment | |
|---|---|
 Seal of the Under Secretary of Defense for Acquisition and Sustainment | |
 Flag of an Under Secretary of Defense | |
 Incumbent since 15 April 2022William A. LaPlante | |
| Office of the Secretary of Defense | |
| Style | Mr. Under Secretary |
| Reports to | Secretary of Defense Deputy Secretary of Defense |
| Appointer | The President with Senate advice and consent |
| Term length | No fixed term |
| Formation | 2018 |
| Succession | 5th in SecDef succession |
| Deputy | Deputy Under Secretary of Defense for Acquisition and Sustainment |
| Salary | Executive Schedule, Level III |
| Website | www |
The Under Secretary of Defense for Acquisition and Sustainment, or USD (A&S), is the Principal Staff Assistant (PSA) and advisor to the Secretary of Defense for all matters relating to acquisition and sustainment in the Department of Defense. This includes the DoD Acquisition System; system design and development; production; logistics and distribution; installation maintenance, management, and resilience; military construction; procurement of goods and services; material readiness; maintenance; environment and energy resilience (including renewable energy); utilities; business management modernization; International Armaments Cooperation, Cooperative Acquisition and International Agreements, Promoting exportability of military components to allies and partners; nuclear, chemical and biological defense programs; and nuclear command, control, and communications.
Ellen Lord became the first Under Secretary of Defense for Acquisition and Sustainment on 1 February 2018, after serving as the final Under Secretary of Defense for Acquisition, Technology, and Logistics.
The Under Secretary is appointed from civilian life by the President with the consent of the Senate to serve at the pleasure of the President.