Randy Hargrove, a spokesman for Walmart, said it wasn't clear how many workers would sign up for the coverage, the Los Angeles Times reported. He said more than half of the Bentonville, Ark., company's 1.3 million U.S. workers are covered by its health insurance plan.
Walmart, the largest private employer in the United States, outlined the benefits expansion in a postcard sent to workers this week.
Hargrove said to qualify, company associates must "live together in an ongoing, exclusive, committed relationship similar to marriage" with a same- or opposite-sex spouse or unmarried partner and "have been together at least 12 months and intend to continue sharing a household indefinitely."
"Since we operate in all 50 states, we thought it was important to develop a single definition so we can ensure consistency for all our associates across the country," Hargrove said.
Notable deaths of 2014 [PHOTOS]