Couples often report significant change in their sexual experiences due to age-related physical symptoms that appear in mid to later life. However, previous research primarily focuses on changes in sexual frequency and satisfaction among different-sex couples. Sexual motives, or the reasons why individuals engage in sexual activities, are also an important component of sexual experiences and may change in different ways for aging same-sex and different-sex spouses. Therefore, the aims of this study are to examine change in sexual motives across a 6-year period in mid to later life among men and women in same-sex and different-sex marriages. Because both spouses’ characteristics can influence a couple’s sexual experiences, we used Actor Partner Interdependence Model (APIM) to explore how respondents’ and their partners’ stress, health, and well-being are related to changes in sexual motives and whether these associations differ for same-sex and different-sex couples. Data are from two waves of the Health and Relationships Project (N = 610 individuals). Results suggest that intrinsic sexual motives (i.e., having sex for pleasure or enjoyment) decline over time, but in different ways by couple type. Among men married to men, intrinsic sexual motives decline only for those with partners who had worse health and higher stress. Among women married to men, intrinsic sexual motives decline only for those with partners who had better health and lower stress. Extrinsic sexual motives (i.e., having sex to please one’s spouse) decline only for men married to men when respondents or their partners had worse health or higher stress. Results show that changes in sexual motives and correlates of these changes vary for men and women in same-sex and different-sex marriages, which underscore the importance of considering gender and sexuality in studying changes in sexual experiences in mid to later life.