Although many children are raised by more than two adults who function as parents, the law rarely entertains the possibility that a child could have more than two legal parents. In a stepfamily situation, for example, a child’s custodial parent has remarried and the stepparent may function as a parent. As long as the child also has a noncustodial parent, the stepparent customarily cannot attain the status of a legal parent.

Lesbians and gay men may wish to form families with more than two parents in a number of situations. Like children of heterosexual couples, a child raised from birth by a same-sex couple may acquire a stepparent if the parents separate and acquire new partners or spouses. Because partners in same-sex couples do not both ...