Traditionally, families were organized patrilineally into lineages and clans. Also, extended families were common and highly valued. As a result of Spanish-colonial influences, however, the family structure of the Poqomam has been altered. Presently, the nuclear family is the most common form of organization. Nevertheless, extended-family households do exist for reasons of economic and emotional interdependence. Kinship terms are of the Eskimo type, placing emphasis on generational differences.
Kinship is traced through both the mother and the father, producing a bilateral rather than a patrilineal system; however, there are vestiges of the traditional family apparent in some current practices. Although villagers believe that they are all related to each other, marriage partners are limited by surname. That is to say, individuals with the same patrilineal surnames are not to marry. In this way, the village as a whole can be thought to loosely represent a clan, and all those with the same patrilineal surname can be thought to loosely represent the members of a patrilineal lineage.