A
ACF - Administration for Children and Families
AHRQ - Agency for Healthcare Research and Quality
AMS - Agricultural Marketing Service
AMTRAK - America, Travel and Track (organization created in 1971 to provide rail passenger service across the U.S.)
AO - Authorizing Official
AP - access point
API - application programming interface
APHIS - Animal and Plant Health Inspection Service
ARPANET - Advanced Research Projects Agency Network (U.S. Department of Defense (DoD) agency created in 1969)
ASBCA - Armed Services Board of Contract Appeals
ATF - Bureau of Alcohol, Tobacco, Firearms and Explosives (agency created in 1972 under the Treasury Department - transferred to the Department of Justice by the Homeland Security Act of 2002)