DEN, KDEN, DIA — which one is right?
- DEN — The IATA code. Used on every commercial ticket and bag tag. This is the one you type into flight search.
- KDEN — The ICAO code. Used by pilots, air traffic control, and flight planning tools. The K prefix identifies it as a contiguous-U.S. airport.
- DIA — A nickname, standing for Denver International Airport. Used conversationally by locals; never used by airlines.
Why DEN and not DIA?
When the new airport opened in February 1995, it absorbed all operations and the IATA code from the old Stapleton International Airport, which had been using DEN for decades. IATA generally avoids reassigning codes to prevent confusion in legacy booking systems, so DEN rode over to the new facility. If the new airport had been created fresh, DIA would have been a natural fit — but it was not.
Airlines at DEN by concourse
DEN has one terminal (Jeppesen) and three concourses. Here is who flies from where — useful whether you are meeting someone or just want to know where you land.
| Concourse | Main Airlines | Access |
|---|---|---|
| A | Air Canada, British Airways, Lufthansa, JetBlue, Alaska (some), Icelandair, Aeromexico | Train or pedestrian bridge |
| B | United Airlines (hub) | Train only |
| C | Southwest, American, Delta, Frontier, Spirit, Sun Country | Train only |
Assignments occasionally shift — confirm on your boarding pass.
Quick facts about DEN
- Full name: Denver International Airport
- IATA code: DEN
- ICAO code: KDEN
- Opened: February 28, 1995
- Size: 33,500 acres (largest U.S. airport by area)
- Annual passengers: Over 82 million (3rd-busiest in the U.S.)
- Runways: 6
- Elevation: 5,434 ft above sea level — affects takeoff roll and fuel loads