Same-Sex Marriage and Gains in Employer-Sponsored Insurance for US Adults, 2008-2017.

Objectives. To estimate the effects of same-sex marriage recognition on health insurance coverage.Methods. We used 2008-2017 data from the American Community Survey that represent 18 416 674 adult respondents in the United States. We estimated changes to health insurance outcomes using state-year variation in marriage equality recognition in a difference-in-differences framework.Results. Marriage equality led to a 0.61 percentage point (P = .03) increase in employer-sponsored health insurance coverage, with similar results for men and women.Conclusions. US adults gained employer-sponsored coverage as a result of marriage equality recognition over the study period, likely because of an increase in dependent coverage for newly recognized same-sex married partners.