Three-letter callsign

This is a list of radio and television broadcasting stations in the United States that are currently assigned three-letter call signs.

Overview

In the United States, all radio and television broadcasting stations that are licensed by the Federal Communications Commission (FCC) are assigned official, unique call signs. Organized broadcasting began in the U.S. in the early 1920s on the AM band — FM and television did not exist yet. Initially most broadcasting stations were assigned three-letter calls; however, a switch was made in April 1922 to primarily four-letter calls, after the number of stations had increased into the hundreds. For a few years thereafter, a small number of new three-letter calls continued to be issued. Although most of the original three-letter calls were randomly assigned, these later calls were often specially requested to match station slogans. The last new three-letter call was assigned to station WIS ("Wonderful Iodine State", now WVOC) in Columbia, South Carolina, on January 23, 1930. Since then, three-letter calls have only been assigned to stations, including FM (beginning in 1943)^[1] and TV (beginning in 1946),^[2] which are historically related to an AM station that was originally issued that call sign. (FCC rules also permitted analog Low Power TV stations to receive three letter calls, with -CA or -LP suffixes,^[3] although there is no record that this ever happened.)

This review only includes FCC-licensed stations. Not included are unlicensed operations, such as carrier current, cable TV, and Internet stations — for example, San Diego State University's "KCR" — which have adopted call-letter-like identifiers that are not officially issued by the FCC. Also not included are stations which use, as slogans, three-letter truncations of their official four-letter call signs; for example, the full call sign for radio station "KOH" in Reno, Nevada, is actually KKOH, and "WTN" in Nashville, Tennessee, is actually WWTN.

Examples of stations which formerly had three letter call signs, but have since changed (such as Albuquerque, New Mexico's KKOB, formerly KOB) are reviewed in separate sections below the main list.

As of February 19, 2026, a total of 102 AM, FM and TV stations in the United States were assigned three-letter call signs. This is divided among only 67 different three-letter calls, because in many cases the same "base" call sign is used by more than one station, although a given call sign is never assigned to more than one AM, FM or TV station. These 67 different "base" three-letter call signs are currently grouped as follows:

• 24 AM-only
• 8 FM-only
• 7 TV-only
• 14 AM/FM
• 7 AM/TV
• 7 AM/FM/TV

Current assignments

Listed below are all the assignments as of February 19, 2026.

• All three-letter call signs originated with an AM-band station in the period 1921 to 1930. In some cases, this station subsequently changed to a different call sign. In these cases, the original station, and its latest call sign, is listed in parentheses
• In cases where an AM station exists with the same "base" call letters as an FM station, the FM station is required to include an "-FM" suffix as part of its call sign. If no AM station is currently using the same base call sign, then the "-FM" suffix is optional.
• As with FM stations, if an AM station currently exists with the same "base" call, a TV station must include a suffix to differentiate itself, but this suffix is optional if no AM station currently exists. TV stations may select either "-TV" or "-DT" as their suffix.

Former usage

In all cases, a given three-letter call sign originated with an AM band station. However, the later development of FM and TV stations saw many adopting a version of the well established AM station's call sign. This was particularly true of FM radio stations, which commonly simulcast an AM station before adopting their own formats and distinctive call letters. Below are partial lists of previous usage:

Other stations of note

• WWV - Fort Collins, Colorado — shortwave time signal data radio clock service operated by the National Institute of Standards and Technology
• KPH - Bolinas, California — shortwave morse code data service operated by radiomarine.org under the auspices of the National Park Service
• NOF - early 1920s station, located in the Anacostia section of Washington, D.C.
• NAA - Arlington, Virginia, station, best known for broadcasting time signals.
• WHD-TV - 1996-1999 Washington, D.C. "model" station, used to develop the digital TV transmission standard.
• WJY - temporary Hoboken, New Jersey, longwave station, which broadcast the July 2, 1921, Dempsey-Carpentier heavyweight boxing match.
• WQB - early 1920s Hartford, Connecticut, station that provided a broadcast service, but was never licensed as a broadcasting station.
• WVP - Army Signal Corps station on Bedloe's Island in New York harbor, which held nightly broadcasts in 1922

References

External links

• Media Bureau Call Sign Actions (Monthly U.S. Federal Communications Commission Public Notices, suspended after July 1, 2022 issue)
• Call Sign Search (FCC Licensing and Management System)

See also

• List of local television stations in North and Central America
• Lists of radio stations in North and Central America