This Essay takes a critical look at the tax fallout from the U.S. Supreme Court’s decision in United States v. Windsor, which declared Section 3 of the federal Defense of Marriage Act (DOMA) unconstitutional. The Essay first describes the path that led to the decision in Windsor. Then, it turns to describing the ways in which the post-Windsor tax terrain may actually be worse for same-sex couples than the bleak tax landscape that they faced before that decision. Under DOMA, same-sex couples already faced a debilitating level of uncertainty in determining how the federal tax laws applied to their relationships. Post-Windsor, same-sex couples will see this uncertainty multiply—even after receiving guidance from the IRS on the implementation of the Windsor decision in the federal tax context. They will have to grapple not only with lingering questions surrounding the federal tax treatment of relationships that are not recognized, but also with new questions regarding whether and how their relationships will be recognized for federal tax purposes. Moreover, it seems that dispatching discrimination designed to erode the progress of same-sex couples toward formal equality has served only to entrench the privileged status of marriage in our federal tax laws rather than foster the recognition of a broader array of human relationships.