§73.879 prohibits an LPFM station from rebroadcasting the signals of another full-power radio station (commercial or noncommercial). Because of the COVID-19 emergency, the FCC has been entertaining requests for waivers of the rule for a temporary period of time (3 months or if the federal state of emergency is lifted, whichever is earlier. Extensions will be reviewed on a case by case basis). As of March 19, 2020, the FCC has already granted this authority to two LPFM stations, one for a commercial station and the other for a noncommercial station.
This request must be made on a special temporary authority (Legal STA) form. Advance permission is required before an LPFM can rebroadcast other radio station, even during an emergency.
Of course, permission of the broadcaster the LPFM is trying to relay must be first obtained. All correspondence should be kept in your station records until the next renewal period.