Walmart workers this week filed a class action lawsuit against the retail giant, alleging that it discriminated against same-sex couples.

The suit, filed on behalf of Walmart employees by the Gay and Lesbian Advocates and Defenders (GLAD) and the Washington Lawyers Committee for Civil Rights and Urban Affairs, contends that the store’s policy of discrimination violates the federal Civil Rights Act.

GLAD has represented the primary plaintiff in the case, Jacqueline Cote, since last fall when it filed a charge of discrimination against Walmart with the federal Equal Employment Opportunity Commission (EEOC).

Massachusetts legalized same-sex marriage in 2004. Cote, a Massachusetts resident and Walmart employee since the late 1990s, had tried for years to add her wife, Diana Smithson, to her employee-sponsored health insurance plan. But during each open enrollment period, when Cote logged into Walmart’s employee benefits website, she had to choose her spouse’s gender.

“I would click ‘female,’ and it would tell me I could not proceed and I needed to call the home office [in Arkansas],” Cote told the Atlantic in an interview. Cote was denied by the company every year during open enrollment. Smithson was diagnosed with ovarian cancer in 2012 and was forced to pay her medical bills with no private insurance.

Walmart changed its policy and began offering same-sex spousal benefits in 2014. But by that point, Smithson had racked up $100,000 in medical expenses.

The EEOC found in January that Walmart likely had discriminated against Cote and Smithson because of their gender. The agency also said that Cote had the right to sue the company, leading to the case filed on Tuesday.

Walmart is the largest private employer in the United States and had $16 billion in profits in 2013, according to Americans for Tax Fairness. A Forbes calculation estimates that the Walton family, which founded the company, have a net worth of $178.1 billion.

This is hardly the first time Walmart has found itself in legal trouble, as the retail giant was found guilty in December of intimidating workers.

National Labor Relations Board administrative law judge Geoffrey Carter found that a Walmart manager had illegally intimated workers by telling employees that co-workers returning from a one-day strike would have to look for a new job, as reported by the New York Times.

Carter also ruled, the Times continued, that one Walmart manager had engaged in unlawful intimidation when he told an Our Walmart supporter, who had a rope tied around his waist in order to pull a heavy load of merchandise, “If it was up to me, I would put that rope around your neck.”