The Obama Administration and his Justice Department have stated they can no longer defend the constitutionality of the federal Defense of Marriage Act (DOMA). However, the final say on this subject (whether marriage can be restricted to the legal union between a man and women) is likely to be settled by the Supreme Court, and probably not for a year or more.
In the meantime, legally married same-sex couples can file protective refund claims for all open tax years if they would benefit on their taxes by joint filing. If these protective refund claims are filed and the Supreme Court strikes down DOMA, you'll be entitled to your refunds.
It should be noted that DOMA impacts more than just income taxes. Were DOMA to be held unconstitutional, the following would also be affected:
- Gifts between spouses would get the unlimited gift tax marital deduction;
- Bequests to surviving spouses would not be subject to estate taxes and the survivor would be entitled to any unused estate tax exemption of the decedent;
- Employer provided health care for same-sex spouses would be tax free.