From the FCC website:
The FCC has three Regional Offices, 16 District Offices, and nine Resident Agent Offices located across the United States.
The FCC's three Regional Offices, covering the Northeast, South Central, and Western regions of the nation are located in Chicago, IL, Kansas City, MO, and San Francisco, CA, respectively.
The 16 District Offices are located in Atlanta, GA: Boston, MA; Chicago, IL; Columbia, MD; Dallas, TX; Denver, CO; Detroit, MI; Kansas City, MO; Los Angeles, CA; New Orleans, LA; New York, NY; Philadelphia, PA; San Diego, CA; San Francisco, CA; Seattle, WA; and Tampa, FL.
The eight Resident Agent Offices are located in Anchorage, AK; Buffalo, NY; Honolulu, HI; Houston, TX; Miami, FL; Norfolk, VA; Portland, OR; and San Juan, PR.