Coahuitlán Totonac is spoken in Veracruz, Mexico, and has been variously ascribed to two different branches of the Totonacan family tree. While recent work has begun to bring empirical evidence to the internal structure of this family tree, there remain several important areas of disagreement, in addition to the disputed affiliation of Coahuitlán. This article informs the family tree and demonstrates that Coahuitlán belongs to the Northern branch using shared innovations and two computational methods. The comparative method seeks sets of shared innovations for evidence of subgrouping. This article presents proposed shared innovations in phonology, morphology, and lexicon, which fall into two sets, one belonging to the Sierra and Lowland branches, and the other belonging to the Northern. Coahuitlán Totonac overwhelmingly shares innovations found in Northern languages and lacks innovations found in Sierra. Two quantitative methods are also used to show that Coahuitlán groups groups closely with other Northern languages.