A Wal-Mart employee sued the retailer on Tuesday, saying its prior policy of denying health insurance to the spouses of gay employees violated gender discrimination laws.
The lawsuit, filed in U.S. District Court in Boston, seeks nationwide class-action status.
Wal-Mart, the largest private U.S. employer, began offering health insurance benefits to same-sex spouses last year, after the U.S. Supreme Court in 2013 struck down part of the Defense of Marriage Act that denied federal benefits to married gay couples.
Jackie Cote, who has worked at Walmart stores in Maine and Massachusetts since 1999, said in the lawsuit that her wife, Diana Smithson, developed cancer in 2012 and the denial of insurance led to more than $150,000 in medical debt.
Cote and Smithson were married in Massachusetts in 2004 after a court ruling made the state the first to allow gay nuptials.
Smithson worked for Wal-Mart until 2008, when she left to care for Cote‘s elderly mother, according to the lawsuit. The company then repeatedly denied requests by Cote to add her wife to her insurance policy. Smithson is now in hospice care, Cote said.
Last year, Cote filed a complaint with the U.S. Equal Employment Opportunity Commission, which said in January that Wal-Mart violated gender discrimination laws by denying benefits to Smithson. Wal-Mart had said federal anti-discrimination laws did not apply to gay employees.
Allison Wright, a lawyer with Gay & Lesbian Advocates & Defenders, which filed the lawsuit, said the group believed other large companies have similar policies in place that could be open to legal challenges.
Cote‘s lawsuit said Wal-Mart‘s previous policy was a form of gender discrimination since the wife of a male employee would have received health insurance, and even after the 2014 change, Wal-Mart workers still live with the uncertainty of losing spousal coverage.
"Benefits provided by Wal-Mart as a matter of grace … are not secure and could potentially be withdrawn just when large health care costs are incurred," the lawsuit says.
A Wal-Mart spokesman said in a statement that the company‘s benefits coverage before the 2014 change was legal. He declined to comment further, saying the company had not yet seen the details of the lawsuit.
The lawsuit seeks to certify a class of current and former gay Wal-Mart workers who were married before Jan. 1, 2014, and various damages for employees, including the value of benefits that were denied and any out-of-pocket medical expenses.
The Supreme Court last month said the U.S. Constitution provided same-sex couples the right to marry, making their marriages legal in all 50 states.
The case is Cote v. Wal-Mart Stores Inc, U.S. District Court for the District of Massachusetts, case number 15-cv-12945.