MONTPELIER, VERMONT — The state of Vermont has joined Connecticut and New York in asking that the federal law defining marriage as between a man and a woman be ruled unconstitutional.

On Friday, Vermont Attorney General William Sorrell said that the Defense of Marriage Act (DOMA) discriminates against same-sex couples, and unfairly denies the, federal benefits.

“These married couples— our friends and neighbors in Vermont—have every right to fair and equal treatment by the federal government,” said Sorrell. “Instead, they are denied Social Security benefits, tax exemptions, and health and retirement benefits.”

The three states filed their briefs in the New York-based 2nd U.S. Circuit Court of Appeals, in a case brought by a New York woman who was required to pay $350,000 in estate taxes when her partner died. Last year, U.S. Attorney General Eric Holder announced that the Justice Department would no longer defend DOMA in court, and several federal judges—including a number appointed by Republican presidents—have ruled the law to be unconstitutional. In June, a federal judge in New York ruled DOMA to be unconstitutional because it intrudes upon the states’ business of regulating domestic relations.

Currently, same-sex marriage is legal in Connecticut, Iowa, Massachusetts, New Hampshire, New York, Vermont, and Washington, D.C.H.