This chapter examines whether marriage will change lesbian and gay couples, with particular emphasis on the benefits that marriage provide to same-sex couples. In assessing the impact of the right to marry on lesbian and gay people as individuals and as members of same-sex couples, the chapter draws insights from Europe and the United States. It argues that critics of same-sex marriage underestimate positive gains to the community while overstating potential downsides. More specifically, it suggests that the institutional and social supports provided by marriage often result in good outcomes for individuals. For example, removing formal discrimination by allowing gay marriage will have positive mental health effects on individual lesbian, gay, and bisexual people. The chapter concludes with a discussion of the effect of marriage on relationships.