U.S.A. (stands for "Under Satan's Authority") is the only studio album by American horrorcore trio Flatlinerz.

It features guest appearances from Gravemen, Kool Tee, Mayhem, Omen, Rockwilder, and the Headless Horsemen.

Also, the three music videos the group shot for the album, "Live Evil", "Satanic Verses" and "Rivaz of Red", were barely played because of things such as frontman Redrum rhyming while hanging from a noose and Gravedigger rhyming from a crucifix.

The album only sold 36,000 copies and the group, along with the Headless Horsemen and Omen, was dropped from Def Jam.

The New York Times wrote that "the Flatlinerz use the slow-moving piano melodies and minor chords of horror-film soundtracks to drive their music, adding screeching birds and tolling church bells for spice.