This paper argues that courts and legislatures should recognize and protect adult relationships other than marriage, in two ways. First, couples in committed, cohabitating relationships should be protected when their relationship dissolves—even if they are not formally married. The law in this area is currently inconsistent and confusing, and should be cleaned up to reflect the reality of the lives of committed couples in need of legal protection. Second, all states should establish a registration scheme along the lines of Colorado’s designated beneficiary law, which allows couples to flexibly design their legal relationship. This status should include specific arrangements about the ownership of property over the course of a long relationship, and should also be expanded to allow people to enter into more than one such relationship at a time, as long as the rights and obligations are not inconsistent. Given the number of couples operating outside of traditional marriage today, these two reforms will increase certainty of legal outcome and better protect the reliance interests of those in committed relationships.