OMAHA, Neb. (AP) — Nearly all Nebraska school districts and some cities and counties will soon begin offering insurance benefits to legally married same-sex couples.

The changes are being made in response to last June's U.S. Supreme Court ruling that negated a critical part of the federal Defense of Marriage Act, which prohibited the government from recognizing same-sex marriages.

Blue Cross Blue Shield recently decided to change its policy effective Jan. 1 because of the high court's ruling, and that company insures all but three of the state's 249 school districts through the Educators Health Alliance.

The Human Rights Campaign, which is the nation's largest advocacy group for lesbian, gay, bisexual and transgender, tracks this issue. That group says 67 percent of Fortune 500 companies offer same-sex partner benefits, so Nebraska is lagging behind other states in offering them.

Sarah Warbelow, who tracks state legislative issues for the Human Rights Campaign, said many employers choose to offer benefits to same-sex couples as part of their efforts to be inclusive and competitive.

"The court ruling has drawn additional attention to the issue, but I don't think the court ruling is driving it. It's just good business," Warbelow said.

After the Supreme Court ruling, the Internal Revenue Service and U.S. Labor Department ruled that widows and widowers who had been legally married could collect their late same-sex spouse's pension benefits.

Nebraska doesn't recognize same-sex marriage, and the state constitution dictates that only marriages between a man and a woman will be recognized.

Warbelow said a few other states that ban gay marriage have decided to provide domestic partner benefits.

Papillion City Administrator Dan Hoins said he thinks the state constitution's ban on same-sex marriage prohibits cities, including his in the Omaha suburbs, from offering benefits to same-sex spouses.

"If state law changes tomorrow, so will we," Hoins said.

Counties and cities in Nebraska aren't covered by a group health insurance plan like the school districts, so they'll each make their own decisions about whether to extend benefits to same-sex spouses or domestic partners. The results have been mixed so far.

The city of Omaha decided this fall that it wouldn't offer health insurance and dental benefits to spouses of legally married gay employees because those benefits aren't called for in current union contracts. City officials say those benefits will have to be negotiated in future contracts.

But Douglas County, which is home to Omaha, will extend benefits to same-sex spouses of employees starting on Jan. 1.

Lancaster County officials have discussed making a similar change, but they decided to delay their decision until they complete more research.

Lincoln officials have said they will decide whether to offer same-sex benefits in 2014.

The state of Nebraska doesn't offer insurance to same-sex spouses.

But the University of Nebraska does offer benefits to same-sex spouses and domestic partners who meet certain criteria at its campuses in the state.

It wasn't immediately clear Monday how many of the 70,000 people covered by Blue Cross for the Educators Health Alliance might take advantage of the coverage for same-sex spouses. School district employees will have until Jan. 31 to sign up for benefits.

The only school districts not affected by the Blue Cross change are Millard, Wayne and York because those districts are self-insured.