At first, KFUO had to share frequences with other stations. The FCC approved the station to move to 830 kHz on July 1, 1940. By September 1941, the FCC reassigned the station to 850 kHz, where it has remained to this day. It also received a "limited time" license because this was the same frequency as KOA in Denver. KFUO can only operate between 80.5 and 102.5 hours per week. The exact hours depend on the times of sunrise and sunset in Denver.