Endothyroid foraminifers are common in most marine Pennsylvanian units in the Appalachian Basin. The genera Planoendothyra Reitlinger, 1959, and Endothyranella Galloway and Harlton, 1930, are the dominant taxa. Scarce Endothyra Phillips, 1846, are restricted below the Desmoinesian. The greatest change in stratigraphic distribution of taxa occurs at the Atokan-Desmoinesian boundary. Sixteen taxa are recognized. Five new species are proposed, including Planoendothyra orbiculata, P.? associata, Endothyranella kentuckyensis, E. inflata, and E. intermissa. Most taxa are assigned previously described American species using a cf. designation. Description and thin section illustration provide a basis for nomenclatural acceptance of these taxa.