The species of Pantherophis were previously currently included in the genus Elaphe. However, in 2002 Utiger et al. raised a taxonomic suggestion to resurrect the genus Pantherophis based on mitochondrial DNA evidence suggesting that the New World ratsnakes are more closely related to the Lampropeltini than to the Old World ratsnakes . This was confirmed by later phylogenetic studies 
Suggested species included:
- Eastern ratsnake (Pantherophis alleghaniensis) HOLBROOK 1836
- Baird's ratsnake (Pantherophis bairdi) YARROW 1880
- Great Plains ratsnake (Pantherophis emoryi) BAIRD & GIRARD 1853
- Eastern fox snake (Pantherophis gloydi) CONANT 1940
- Corn snake (Pantherophis guttatus) LINNAEUS 1766
- Western ratsnake (Pantherophis obsoletus) SAY 1823
- Slowinski's corn snake (Pantherophis slowinskii) BURBRINK 2002
- Central ratsnake (Pantherophis spiloides) DUMÉRIL, BIBRON & DUMÉRIL 1854
- Western fox snake (Pantherophis vulpinus) BAIRD & GIRARD 1853
In recent years there has been some taxonomic controversy over the genus of North American ratsnakes. Based on mitochondrial DNA, Utiger et al. (2002) showed that North American Rat Snakes of the genus Elaphe along with closely related genera such as Pituophis and Lampropeltis form a monophyletic group separate from Old World members of the genus. They therefore suggested the resurrection of the available name Pantherophis Fitzinger for all North American taxa (north of Mexico).
The SSAR (2008) accepted the taxonomic change to Pantherophis 
- ↑  Molecular Systemics and Phylogeny of Old and New World Ratsnakes
- ↑ Pyron, R.A. & F.T. Burbrink (2009) Neogene diversification and taxonomic stability in the snake tribe Lampropeltini (Serpentes: Colubridae). Mol. Phylogenet. Evol. 52: 524-529
- ↑ Elaphe obsoleta at The Center for North American Herpetology. Accessed 20 June 2008.
- ↑ name="Cro08">Crother, B. I. (ed.). 2008. Scientific and Standard English Names of Amphibians and Reptiles of North America North of Mexico, pp. 1–84. SSAR Herpetological Circular 37. PDF at SSAR. Accessed 4 July 2011.