Same-sex partners who want to participate in a state long-term care program can move forward with a federal lawsuit, a federal judge has said.

Judge Claudia Wilken denied the U.S. government’s request to dismiss the case, which challenges the U.S. Treasury Department and the California Public Employees’ Retirement System over the federal 1996 Defense of Marriage Act (DOMA). The decision was filed on Jan. 18 in the U.S. District Court for the Northern District of California.

More than 160,000 state workers have purchased long-term care insurance through the California Public Employees’ Retirement System, but CalPERS has said same-sex employees cannot enroll in the long-term care insurance program.

The reason, according to court records, is that the system has “no choice but to follow federal tax law” as CalPERS is “a tax-qualified plan for IRS purposes.”

Since DOMA recognizes a spouse only as someone of the opposite sex, the plaintiffs, who are California state employees married to partners of the same sex, cannot enroll.

CalPERS is the lowest-cost long-term care insurance plan, court records state, although the federal government argued the plaintiffs lack injury and could seek insurance elsewhere. Long-term care insurance can provide for care in an assisted living or skilled nursing facility, or cover services not paid for by Medicare, Medicaid or private health insurance.

Wilken disagreed with the federal government, writing that the plaintiffs “have stated a cognizable claim for violation of their rights to substantive due process.”

“CalPERS’ exclusion of same-sex spouses from its LTC program is an example of the restraint on states’ authority to extend legal recognition to same-sex marriages,” she wrote. “CalPERS has made it clear that its exclusion is an effort to comply with federal requirement for tax benefits.”