Distribution and host use of the 9 species of Neoechinorhynchus (Acanthocephala: Neoechinorhynchidae) described from turtles are summarized from a comprehensive evaluation of the specimen base in the major parasitology museums of the United States. Each specimen in each lot was examined and its identity verified, if possible. Verified specimens were used to construct a specimen-based known distribution and list of definitive hosts for each species. Five species (Neoechinorhynchus chrysemydis, Neoechinorhynchus emydis, Neoechinorhynchus emyditoides, Neoechinorhynchus pseudemydis, and Neoechinorhynchus stunkardi) have broad distributions in North America, whereas Neoechinorhynchus chelonos and Neoechinorhynchus lingulatus are currently known only from eastern states, and Neoechinorhynchus magnapapillatus is known from the eastern Atlantic seaboard, Florida, and the coast of the Gulf of Mexico. Neoechinorhynchus schmidti is known only from Mexico. Host use is confined largely to emydid turtles; reports from turtles in other families are sporadic, and most of the turtle species of North America have not been surveyed adequately for acanthocephalans. The specimen base for the species of Neoechinorhynchus of turtles is unsuitable for most taxonomic purposes; it is composed of small lots of specimens with few identifiable worms that are, on average, in poor physical condition. Future biodiversity studies of this group will require significant new specimen collections to answer questions of host use, evolutionary relationships, and biogeography.