Inequities in marriage laws and domestic partnership benefits may have implications for who bears the burden of health care costs. We examined a recent period in California to illuminate disparities in health insurance coverage faced by same-sex couples. Partnered gay men are less than half as likely (42 percent) as married heterosexual men to get employer-sponsored dependent coverage, and partnered lesbians have an even slimmer chance (28 percent) of getting dependent coverage compared to married heterosexual women. As a result of these much lower rates of employer-provided coverage, partnered lesbians and gay men are more than twice as likely to be uninsured as married heterosexuals. The exclusion of gay men and women from civil marriage and the failure of domestic partnership benefits to provide insurance parity contribute to unequal access to health coverage, with the probable result that more health spending is pushed onto these individuals and onto the public.