| 1 | US | US Airways, Inc. | ICAO: USA, Callsign: US Air, IATA Prefix: 037, ICAO designator changed to AWE. ICAO callsign changed to Cactus. Name changed from US Air | USA | AVCODES |
| 2 | US | Piedmont Airlines, Inc. d/b/a USAir Express | ICAO: PDT, Callsign: Piedmont, IATA designator changed to PT | USA | AVCODES |
| 3 | US | Chautauqua Airlines, Inc. d/b/a USAir Express | ICAO: CHQ, Callsign: Chautauqua, IATA designator changed to RP* | USA | AVCODES |
| 4 | US | Allegheny Commuter Airlines, Inc. d/b/a USAirways Express | ICAO: ALO, Callsign: Allegheny, Name changed from Allegheny Commuter Airlines, Inc. dba USAir Express. Ceased operations. | USA | AVCODES |
| 5 | US | USAir | ICAO: USA, IATA Prefix: 037, Name changed to US Airways | USA | AVCODES |
| 6 | US | Allegheny Commuter Airlines, Inc. d/b/a USAir Express | ICAO: ALO, Callsign: Allegheny, IATA Designator changed from AL | USA | AVCODES |
| 7 | US | Allegheny Commuter Airlines, Inc. d/b/a USAir Express | ICAO: ALO, Callsign: Allegheny, Name changed to Allegheny Commuter Airlines, Inc. dba USAirways Express | USA | AVCODES |
| 8 | US | Unavia Suisse, SA | Callsign: Unavia, | CH | AVCODES |
| 9 | US | US Airways, Inc. | ICAO: AWE, Callsign: Cactus, IATA Prefix: 037, Merged in American Airlines (AA/AAL). ICAO designator changed from USA. ICAO callsign changed from US Air. Name changed from US Air | USA | AVCODES |
| 10 | USA | US Airways, Inc. | IATA: US, Callsign: US Air, IATA Prefix: 037, ICAO designator changed to AWE. ICAO callsign changed to Cactus. Name changed from US Air | USA | AVCODES |
| 11 | USA | USAir | IATA: US, IATA Prefix: 037, Name changed to US Airways | USA | AVCODES |
| 12 | USA | US Airways | IATA: US | | ICAO1 |
| 13 | USA | U.S. DEPT. OF DEFENSE - ARMY, MIL. TRFC. MGMT. & TERM. SERV. | | | PWRC |
| 14 | USA | USA TOURS | | | SCAC4 |
| 15 | USA | US Army | | USA | TRAFFIC |
| 16 | USAA | U.S. DEPARTMENT OF DEFENSE | | | SCAC4 |
| 17 | USAAF | United States Army Air Forces | | USA | TRAFFIC |
| 18 | USAB | U S A TWO THOUSAND (2000) | | | SCAC4 |
| 19 | USAC | USA CONSOLIDATOR | | | SCAC1 |
| 20 | USAC | UNIVERSAL SERVICES AND LOGISTICS LL | | | SCAC4 |
| 21 | USAD | USA TRUCK INC (DEDICATED OPERATIONS | | | SCAC4 |
| 22 | USAF | U.S. DEPT. OF DEFENSE - AIR FORCE | | | PWRC |
| 23 | USAF | US Air Force | | USA | TRAFFIC |
| 24 | USAG | USA COURIERS | | | SCAC4 |
| 25 | USAI | USA MANAGEMENT SYSTEMS INC | | | SCAC4 |
| 26 | USAM | U.S. DEPARTMENT OF DEFENSE | | | SCAC4 |
| 27 | USAO | USA INTERCARGO LLC | | | SCAC4 |
| 28 | USAS | U.S. DEPARTMENT OF DEFENSE | | | SCAC4 |
| 29 | USAT | U.S. DEPT. OF DEFENSE - ARMY TRANSPORTATION CORP. | | | PWRC |
| 30 | USAT | U S A TRANSPORTATION SERVICES INC | | | SCAC4 |
| 31 | USAU | UNITED STATES ARMY | | USA | BIC |
| 32 | USAU | PAN TEXAS LEASING INC. | | | PWRC |
| 33 | USAU | Pan Texas Leasing | | | RSRV |
| 34 | USAU | U S DEPARTMENT OF DEFENSE-ARMY | | | SCAC4 |
| 35 | USAV | U S A VAN LINES LLC | | | SCAC4 |
| 36 | USAW | USA Logistics | | | SCAC2 |
| 37 | USAW | USA LOG CARRIERS LLC | | | SCAC4 |
| 38 | USAW | US Airways | Real: USA, US | USA | TRAFFIC |
| 39 | USAX | United States Asphalt Refining Co. | 8/1920-7/1923 | | NAKINA |
| 40 | USAX | Dept. of the Army, Office of the Chief of Transportation, Movements Division, Tank Car Section | 1/1950-10/1957 | | NAKINA |
| 41 | USAX | Department of the Army, Transportation Materiel Command, Marietta, Pennsylvania | eliminated 10/1955 | | NAKINA |
| 42 | USAX | Department of the Army, Transportation Supply and Maintenance Command, St. Louis 1, Missouri | added 10/1955 | | NAKINA |
| 43 | USAX | Dept. of the Army, Transportation Supply and Maintenance Command | eliminated 7/1958 | | NAKINA |
| 44 | USAX | Dept. of the Army, U.S. Army Transportation Supply and Maintenance Command | added 7/1958 | | NAKINA |
| 45 | USAX | Dept. of the Army, Office of the Chief of Transportation, Movements Division, Tank Car Section | 1/1952-10/1957; eliminated 4/1960 | | NAKINA |
| 46 | USAX | Dept. of Defense, Military Traffic Management Agency | added 4/1960; 4/1961; eliminated 4/1962 | | NAKINA |
| 47 | USAX | Dept. of Defense, Defense Traffic Management Service | added 4/1962; eliminated 7/1965 | | NAKINA |
| 48 | USAX | Dept. of Defense, Military Traffic Management and Terminal Service | added 7/1965; 7/1965-4/1970; eliminated 10/1974 | | NAKINA |
| 49 | USAX | Dept. of Defense, Military Traffic Management Command | added 10/1974; 1/1975; eliminated 7/1975 | | NAKINA |
| 50 | USAX | Dept. of Defense, Troop Support and Aviation Material Readiness Command (intra-plant service) | 1/1980; 1/1994-7/2005 (not listed) | | NAKINA |
| 51 | USAX | Dept. of the Army, Office of the Chief of Transportation, Movements Division, Tank Car Section | 1/52-10/57 | | NRHS |
| 52 | USAX | Dept. of the Army, Transportation Supply and Maintenance Command | eliminated 7/58 | | NRHS |
| 53 | USAX | Dept. of the Army, U.S. Army Transportation Supply and Maintenance Command | added 7/58 | | NRHS |
| 54 | USAX | Dept. of the Army, Office of the Chief of Transportation, Movements Division, Tank Car Section | 1/52-4/61 | | NRHS |
| 55 | USAX | Dept. of Defense, Military Traffic Management Agency | eliminated 4/62 | | NRHS |
| 56 | USAX | Dept. of Defense, Defense Traffic Management Service | added 4/62; eliminated 7/65 | | NRHS |
| 57 | USAX | Dept. of Defense, Military Traffic Management and Terminal Service | added 7/65; 7/65-4/70 | | NRHS |
| 58 | USAX | Dept. of Defense, Military Traffic Management Command | 1/75; eliminated 7/75 | | NRHS |
| 59 | USAX | Dept. of Defense, Troop Support and Aviation Material Readiness Command (intra-plant service) | 1/80-7/2000 | | NRHS |
| 60 | USAX | *UNITED STATES ASPHALT REFINING CO. | | | PWRC |
| 61 | USAX | +U.S. DEPT. OF DEFENSE - TROOP SUPPORT & AVIATION MATERIAL READINESS | | | PWRC |
| 62 | USAX | United States Army | | | RSRV |
| 63 | USAX | DEPT OF ARMY MIL TRFC MGMT & TERM S | | | SCAC4 |
| 64 | USAX | United States Army | | USA | TRAFFIC |
| 65 | USAZ | (XTRZ) XTRA INTERMODAL | | | PWRC |
| 66 | USAZ | XTRA Intermodal | | | RSRV |
| 67 | USAZ | MILESTONE EQUIPMENT CORPORATION | | | SCAC4 |
| 68 | USB | Tusheti | Callsign: Tusheti, | GE | AVCODES |
| 69 | USB | Tusheti | | | ICAO1 |
| 70 | USBC | U S A BOUND CO | | | SCAC4 |
| 71 | USBG | USB FREIGHT INC | | | SCAC4 |
| 72 | USBK | U S BACKHAULER | | | SCAC4 |
| 73 | USBL | UNITED SKY LOGISTICS LIMITED | | | SCAC4 |
| 74 | USBR | US BROTHERS INC | | | SCAC4 |
| 75 | USBT | U S BULK TRANSPORT INC | | | SCAC4 |
| 76 | USBX | U.S. Borax & Chemical Corp. | added 7/1964; 7/1965-10/1966; eliminated 1/1969 | | NAKINA |
| 77 | USBX | North American Car Corp. | added 7/1982; eliminated 1/1984 | | NAKINA |
| 78 | USBX | General Electric Railcar Services Corp. | added 1/1984; 1/1994; eliminated 4/1999 | | NAKINA |
| 79 | USBX | The CIT Group/Capital Finance, Inc. | added 4/1999; 7/2000-7/2005 | | NAKINA |
| 80 | USBX | U.S. Borax & Chemical Corp. | added 7/64; 7/65-10/66; eliminated 1/69 | | NRHS |
| 81 | USBX | North American Car Corp. | added 7/82 | | NRHS |
| 82 | USBX | General Electric Railcar Services Corp. | 1/94; eliminated 4/99 | | NRHS |
| 83 | USBX | The CIT Group/Capital Finance, Inc. | added 4/99; 7/2000 | | NRHS |
| 84 | USBX | *U.S. BORAX & CHEMICAL CORP. | | | PWRC |
| 85 | USBX | +THE CIT GROUP/CAPITAL FINANCE, INC. [(NATX) GENERAL ELECTRIC RAILCAR SERVICES CORPORATION] | | | PWRC |
| 86 | USBX | US Borax & Chemical (CIT Group) | | | RSRV |
| 87 | USBX | CIT GROUP/CAPITAL FINANCE INC, THE | | | SCAC4 |
| 88 | USC | US Check Airlines | Callsign: Starcheck, Name changed to AirNet Systems, Inc. | USA | AVCODES |
| 89 | USC | AirNet Systems, Inc. | Callsign: Starcheck, Name changed to Airnet II, LLC. Name changed from US Check Airlines, | USA | AVCODES |
| 90 | USC | AirNet II, LLC | Callsign: Star Check, Name changed from AirNet Systems, Inc. Name changed from US Check Airlines, | USA | AVCODES |
| 91 | USC | US Check Airlines | | | ICAO1 |
| 92 | USC | UNITED STOCKYARDS CORP. | | | PWRC |
| 93 | USCC | USCS CHEMICAL CHARTERING LLC | | | SCAC4 |
| 94 | USCE | US OCEAN LLC | | | SCAC4 |
| 95 | USCF | USCA FORWARDING - SEABELL EXPRESS I | | | SCAC4 |
| 96 | USCG | USC GROUP INC. | | | SCAC1 |
| 97 | USCG | U S PORT SERVICES INC | | | SCAC4 |
| 98 | USCG | United States Coast Guard | | USA | TRAFFIC |
| 99 | USCH | USS CHARTERING LLC | | | SCAC4 |
| 100 | USCI | USCT INC | | | SCAC4 |
