KNWN in Seattle, Washington, WMVP in Chicago, Illinois and XEOY-AM share Class A status of 1000 AM.
From XEOY-AM, Núcleo Radio Mil was formed, adding XEPH-AM 590, XEMX-AM 1380, XEBS-AM 1410 and XEUR-AM 1530 to the fold.
From the 1950s onward, XEOY's format imitated that of XEW-AM, with general interest and family programming, as well as recorded music.
In 1961, that station became classical music "Estereomil"; it was swapped with XEBS-FM in 1967 to move to 89.7 MHz (now XEOYE-FM), while 100.9 FM is now XHSON-FM (still owned by NRM).
In 2017, the name was changed from Radio Mil to Mil AM, at which time the talk programming began to be phased out and replaced with a musical format again, now consisting of Spanish-language pop from the 1970s to the 2000s, including three daily hours dedicated exclusively to Juan Gabriel, José José and Luis Miguel.