The department said it was moving to clarify those rules and make coverage "more accessible and equitable for married same-sex couples." It's part of a government-wide effort to codify the rights of same-sex spouses in the wake of last year's Supreme Court decision striking down the federal Defense of Marriage Act, and opening the way for same-sex spouses to receive government benefits.
The new HHS policy says that if an insurance company offers spousal coverage to heterosexual couples, it must also provide that benefit to same-sex couples who were legally married in a jurisdiction that recognizes marriage between people of the same sex.
Many large employer plans are already operating under similar rules issued last fall by the Labor Department. These are so-called "self-insured" plans in which an employer sets aside its own money to cover most of the expected medical costs of workers. Self-insured employers generally hire an insurance company to administer their benefit plan.
Friday's HHS rules applies instead to plans that are sold directly by insurance companies to individuals and employers, usually small to mid-sized firms.
There is an exception:
"Grandfathered" plans that were in existence when the health law passed four years ago and have changed very little since then do not have to offer coverage to same-sex spouses. Those plans, however, represent a dwindling share of the market.
The administration said it is urging insurers to voluntarily comply with the new policy right away. It will be a requirement for coverage starting Jan. 1, 2015 or later.