TRENTON, N.J.—New Jersey’s civil unions law has failed to provide all the benefits of marriage to at least one in five same-sex couples, a gay rights group told a panel Sept. 26 that will report its findings to the state’s governor and legislature.

More than 300 of the 1,514 same-sex couples who have joined in civil unions have complained to Garden State Equality, the state’s leading gay rights group, about employers denying them benefits under the law, said David M. Smith, the group’s deputy director.

Smith and more than 20 others shared their experiences with the civil unions law—all negative—during a hearing to review the law’s effectiveness. The law is supposed to provide those who take advantage of it with all the benefits that married couples enjoy.

Craig Ross said that when he lost his white-collar job and tried to get benefits on his partner’s plan, the couple were denied despite their civil union because they aren’t “married.”

“Calling our relationship and our legal status a civil union, I believe, gives my company an easy out,” Ross said.