On June 26, 2013, the United States Supreme Court issued decisions in the cases of U.S. v. Windsor and Hollingsworth v. Perry, two highly anticipated decisions regarding the constitutionality of same-sex marriage in the United States. The results were somewhat mixed: the Court in Windsor determined that the Section 3 of the Federal Defense of Marriage Act ("DOMA") – which defined marriage as between one man and one woman - was an unconstitutional violation of the Fifth Amendment and that the question of permitting (or denying) same-sex marriage is one reserved to the states. However, Section 2 of DOMA, which allows states to refuse to recognize marriages performed in other states, is not affected by the Court's ruling in Windsor.

In Hollingsworth, the Court addressed California's Proposition 8, which defined marriage as between one man and one woman. A Federal District Court found this state voter-approved constitutional amendment to be unconstitutional, and the Ninth Circuit agreed. However, the Supreme Court did not determine this matter on the merits. Rather, the Court held that the official proponents of the constitutional amendment, the only parties seeking relief to redress an alleged injury after the district court's opinion, did not have standing to appeal the district court's order.  Therefore, the result is that the district court's order finding California's Proposition 8 to be unconstitutional will stand.

What do these cases mean for estate planning for same-sex couples living in Michigan? As a result of these cases, under Federal law married same-sex couples must be treated as married opposite-sex couples. As noted by the Court in Windsor, DOMA affected over 1,000 federal statutes. But although the Court struck down DOMA's federal prohibition of same-sex marriage, it also determined that the question of permitting same-sex marriage is one reserved to the states. Moreover, its provision permitting states to not recognize marriages performed in other states stands. In addition, although California's Proposition 8 was repealed,Hollingsworth only addresses California same-sex marriages, which the California Supreme Court previously found to be permitted. 

Therefore, Michigan's voter-approved constitutional amendment prohibiting same-sex marriage still stands. As a result, any federal benefit which relies upon a state definition of marriage – including the marital deduction against federal estate tax, among others – will not be available to a same-sex couple residing in Michigan. Though Windsor and Hollingsworthrepresent a sea change regarding the federal interpretation of marriage, Michigan's interpretation of marriage is unchanged and a decision – if any - on its constitutionality has been left for another day.