| Abbreviation | Definition |
|---|---|
| AMM | Army Medical Museum |
| AMP | Agency Management Plan |
| AMS | Acquisition Method Selection |
| AMS | Agricultural Marketing Service |
| AMS | Award Management System |
| AMS-API | Address Matching System Application Programming Interface |
| AMSARA | Accession Medical Standards Analysis and Research Activity |
| AMTA | Access to Medical Treatment Act |
| AMTA | Agricultural Market Transition Act |
| AMTRAK | National Railroad Passenger Corporation |
| AMTRAK | Railroad line subsidized by U.S. Government (not an acronym) |
| AN | Adult Nationals |
| ANA | Administration for Native Americans |
| ANA | American News Agency |
| ANACI | Access National Agency Check and Inquiries |
| ANC | Arlington National Cemetery |
| ANL | Argonne National Laboratory |
| ANP | Acadia National Park |
| ANPRM | Advanced Notice of Proposed Rulemaking |
| ANS | American National Standards |