A federal appeals court in Boston ruled late last week that a portion of the Defense of Marriage Act (DOMA) is unconstitutional because it violates the rights of same-sex couples who are validly married under Massachusetts law. At issue in the case was a provision of DOMA that says only opposite-sex spouses may be recognized as spouses for purposes of federal law.

This has important implications for employee-benefit plans because several provisions of federal law grant spouses special rights. For example, spouses have survivor rights under retirement plans, and spouses can receive tax-free coverage and have special-enrollment and COBRA rights under group health plans. Under DOMA, these rights do not apply to same-sex spouses, but that could change if DOMA is struck down.

The case does not disturb existing state statutes and constitutional provisions that prohibit the recognition of same-sex marriages. But difficult questions may arise if a same-sex couple that is validly married in one state seeks to enforce rights under federal law against an employer or employee-benefit plan in a state that does not recognize same-sex marriage.

Ultimately, this is an issue that will be addressed by the Supreme Court, and now that a federal appeals court has ruled, review by the Supreme Court could come as early as next year.