By striking down key provisions of the Defense of Marriage Act, the Supreme Court has brought about a major change in the way same-sex couples will be viewed in the eyes of the IRS.

In almost all areas of the Internal Revenue Code — from federal income tax to estate planning — the law carves out special rules that apply for married couples filing joint tax returns. While the ruling does not mean that all states must recognize same-sex marriages, it does mean that the federal government —including the IRS — will be required to treat those same-sex marriages that are recognized as valid for purposes of federal law.

While the ruling obviously represents a major step toward equality in general, in some areas, such as estate and Social Security planning, the ruling also represents a big win (tax-wise) for same-sex couples. High income same-sex clients, however, need to be prepared for the reality that their tax bills might be going up this year.