Few predicted the Supreme Court’s ruling in NFIB v. Sebelius to conclude that the “Individual Mandate” provision of the Patient Protection And Affordable Care Act (PPACA) is not a regulation of interstate commerce, but is instead a tax on persons who do not choose to buy “minimum acceptable” health insurance. This legal theory was addressed in only a few pages of the government’s extensive briefing in the case and occupied practically no time during the unusual, three-day oral arguments. To this day, the Obama Administration, which claims to have won the case, has refused to accept this “Tax Power” theory. Those of us who oppose the law on legal and policy grounds must, however, live with the decision, and, what is harder, try to make sense of it. This article will address some of the questions that remain in the wake of the NFIB decision. In Part I, I review the rationale of NFIB, and one especially significant problem that remains with regard to Commerce and Tax Clause jurisprudence. In Part II, I take the decision’s Tax Power rationale at its word: how does converting the Individual Mandate into a tax change the effect and the constitutionality of the PPACA? In Parts III through V, I address three constitutional problems with the constitutionality of this tax — the Apportionment, Uniformity, and Origination Clauses, respectively. I conclude that, even if recharacterized as a tax, the requirement to buy a health insurance policy is unconstitutional.