List of the busiest airports in the United States Busiest US airports by total passenger boardings Medium hubs

| Rank_2012 | Airports_Medium_Hubs | IATA_Code | City_Served | State_ | _2012 |
|---|---|---|---|---|---|
| 30 | Portland International Airport | PDX | Portland | OR | 7142610 |
| 31 | Lambert-St. Louis International Airport | STL | St. Louis | MO | 6200252 |
| 32 | William P. Hobby Airport | HOU | Houston | TX | 5043708 |
| 33 | Oakland International Airport | OAK | Oakland | CA | 4923435 |
| 34 | Kansas City International Airport | MCI | Kansas City | MO | 4866850 |
| 35 | Nashville International Airport | BNA | Nashville | TN | 4796868 |
| 36 | Austin-Bergstrom International Airport | AUS | Austin | TX | 4606143 |
| 37 | Raleigh-Durham International Airport | RDU | Raleigh / Durham | NC | 4489097 |
| 38 | John Wayne Airport-Orange County | SNA | Santa Ana | CA | 4381956 |
| 39 | Sacramento International Airport | SMF | Sacramento | CA | 4357899 |
| 40 | Cleveland-Hopkins International Airport | CLE | Cleveland | OH | 4325353 |