The four types of family structure are nuclear family, single-parent family, extended family and childless family. Other family structures that are also recognized and are becoming more common are stepfamily and grandparent-led family.
The nuclear family, which is a traditional family with two parents and their children, is still the most common family structure in the United States, with about 70 percent of families falling into this structure. Single-parent families, which consist of one parent raising children, have grown considerably over the past few decades to represent 25 percent of all families. Extended families include two or more adults who are related, often across generations, living in the same household. Childless families consist of a couple with no children.
The stepfamily consists of two separate families merging into a single unit after divorce and remarriage. The grandparent family consists of grandparents raising children when parents are unable to do so.