Sexual minority women are granted more rights today than ever before. However, it is unclear how the relationships of sexual minority women have changed compared to previous decades. Additionally, a large body of work has focused on women's same-sex (e.g., lesbian) relationships without accounting for the unique experiences of bisexual women in their relationships. The current study utilizes two national samples of heterosexual, lesbian, and bisexual women to address these gaps, one cohort from 1995 and a second from 2013. We performed analyses of variance (ANOVAs) to examine the effects of sexual orientation, cohort, and their interaction on relationship support and strain. On average, relationships exhibited higher quality in 2013 than in 1995. When considered together, lesbian and bisexual women exhibited higher relationship support than heterosexual women in 1995, but not 2013. Importantly, examining lesbian and bisexual women as separate groups revealed that bisexual women's relationships were on average characterized by lower support and higher strain than lesbian women. Simple effects indicated that bisexual women in 2013 were at the highest risk for diminished relationship quality, while lesbian and heterosexual women's relationships were either stable or improved in this more recent cohort. Implications for clinical practice as well as future research on sexual minority women is discussed.