Using data from the National Survey of Families and Households, we compared quality of family relationships and well-being across five different family structures with a particular focus on adoptive households. Four theoretical perspectives, each emphasizing the importance of different factors in determining relationship quality and well-being, guided this work and led us to compare adoptive families with families that include two biological parents, single mothers, stepfathers, and stepmothers. We found the most support for the perspective stressing the importance of family processes that occur in all types of families, rather than family structure. Specifically, there were few family structure differences based on fathers' and children's reports, and structure differences in mothers' reports were no longer significant after controlling for disagreements between family members. The implications of these results for adoption theory and policies are discussed.