How do you find three-letter airport codes by state?

The Federal Aviation Administration maintains a database of airport information, including airport codes, that may be searched by various optional filters including region, district, state, county and city. Search results may be viewed online or downloaded.

The Federal Aviation Administration's airport database includes facility and contact information for public and private airports. As of October 2015, clicking the Submit button on the search page leads to a summary page which provides a link to the search results under the Reports section as "Airport Contact Information." The three-letter airport codes for commercial airports may be found in their respective listings in the Location ID field. The search results are alphabetized by city name.