New nomenclatural changes are presented for selected North American mordellid beetles (Coleoptera: Mordellidae). The following five genera are newly recorded fi.路om the United States: Mordellaria Ermisch 1950, Falsomordellistena Ermisch 1941, Mordellina Schilsky 1908, Mordellochroa Emery 1876, and
Pseudotolida Ermisch 1950. The following species are transferred from Tomoxia and represent new combinations: Mordellaria borealis (LeConte 1862), Mordellaria fascifera (LeConte 1878), Mordellaria latipalpis (Ray 1946), Mordellaria serval (Say 1835), and Mordellaria undulata (Melsheimer 1845). The following species are transferred fi.路om Mordellistena and represent new combinations: Falsomordellistena hebraica (LeConte 1862) and Falsomordellistena pubescens (Fabricius 1798); Mordellina blatchleyi (Liljeblad 1945), Mordellina pilosella (Ray 1947), Mordellina pustulata (Melsheimer 1845), Mordellina ustulata (LeConte 1862), and Mordellina wichhami (Liljeblad 1945); Mordellochroa scapularis (Say 1824); Pseudotolida
arida (LeConte 1862), Pseudotolida hnausi (Liljeblad 1945), and Pseudotolida lutea (Melsheimer 1845). Mordellina ustulata (LeConte 1862) represents a return to species rank after being treated as a subspecies of Mordellistena andreae LeConte 1862. There are a total of 17 genera of Mordellidae in America north of Mexico