This is the first study to examine change in depression and anxiety across the first year of adoptive parenthood in same-sex couples (90 couples: 52 lesbian, 38 gay male). Given that sexual minorities uniquely contend with sexual orientation-related stigma, this study examined how both internalized and enacted forms of stigma affect the mental health of lesbians and gay men during the transition to parenthood. In addition, the role of contextual support was examined. Higher perceived workplace support, family support, and relationship quality were related to lower depressive and anxious symptoms at the time of the adoption, and higher perceived friend support was related to lower anxiety symptoms. Lower internalized homophobia and higher perceived neighborhood gay-friendliness were related to lower depressive symptoms. Finally, individuals with high internalized homophobia who lived in states with unfavorable legal climates regarding gay adoption experienced the steepest increases in depressive and anxious symptoms. Findings have important implications for counselors working with sexual minorities, especially those experiencing the transition to parenthood.