Children who live in single-parent or stepparent households have lower academic outcomes than children from two-parent continuously married parents. However, many studies do not differentiate within one-parent family types, masking potential heterogeneity that could be related to academic achievement. Because family structure is increasingly complex, it is important to examine whether its effects on achievement are from the structure itself or from processes within families. Using three increasingly complex family structure typologies, some cases of heterogeneity are found among children in specific types of single-parent and stepparent families, but this variance is often explained by family processes. Further research on nationally representative data is needed to test whether it is important to pursue issues of family structure heterogeneity or whether measures of family processes may reduce the potential need for more complex family structure typologies.