Several recent studies have produced phylogenetic models for the Bivalvia. Although generally agreeing on the monophyly of traditional families, superfamilies, and subclasses, these studies have produced conflicting phylogenetic models regarding the relationships of the included taxa. The present study compares new molecular phylogenies for the 18S, 28S, 16S, and COI genes with five published morphological phylogenies. Most areas of conflict are also areas of poor resolution, suggesting that continued research should resolve the problem. The relationships among pteriomorph orders, among basal veneroid superfamilies, and among protobranch orders remain particularly uncertain.