|Abstract:||Studies documenting economic, social, and even health advantages to stable marriages and quality relationships explain why the indicators and outcomes of long-term relationship stability are of great interest to social scientists. The bulk of research on relationship stability and duration focuses on heterosexual couples. Many same-sex couples maintain long-term relationships akin to marriage, yet little is known about the degree to which these relationships might provide similar advantages to lesbians and gay men. This study uses data from the United States decennial census (2000) to compare demographic, economic, and health differences among non-coupled individuals and those in three different coupling arrangements- different-sex married, different-sex unmarried, and same-sex couples- and explore how these differences correlate and perhaps predict long-term coresidential stability. Findings indicate broad similarity in predictors of stability among different-sex married and same-sex and different-sex unmarried couples. The odds of being in a long-term relationship relative to different-sex married couples are higher for same-sex couples living in states with sexual orientation anti-discrimination laws, suggesting that supportive social and legal climates do impact relationship stability in couples.