Genetic parentage is the predominant theory of parentage. The US Constitution protects genetic parents’ opportunity to parent, and states often treat genetics as sufficient for parentage, at least for child support. No moral principles justify the latter inference. Nor can genetic ties directly justify parental liberties. Consequentialists imagine that family law exploits evolutionary incentives to serve child welfare, but genetics is too crude a proxy for child-rearing quality. Genetic parentage rules poorly realize perfectionist or natural law visions of the procreative family. This purpose is illegitimate. No adult can have a fundamental right to control a child’s life because it serves the adult’s ends. Nevertheless, many reasonable citizens value genetic heritage. They should be free to pursue their vision of a valuable family if consistent with equal respect for the child and other adults. Citizens cannot legitimately object if the law prevents them from using others’ genetic code to create a child to raise themselves. The child has no legitimate objection if the community ensures their genetic parents fulfill the parental role promptly and adequately. Helping families provide adequate care offset the parentage lottery. As constitutional law recognizes, adults have a derived liberty right to raise their genetic children.