The first day of oral arguments before the Supreme Court on the constitutionality of the Affordable Care Act addressed whether the challenges to the Affordable Care Act are barred by the Tax Anti-Injunction Act. As expected, a substantial portion of the oral argument addressed the question of whether the penalty individuals must pay if they have no health insurance is a “tax” within the meaning of the Tax Anti-Injunction Act. However, the arguments also addressed a related question: whether the Tax Anti-Injunction Act deprives courts of jurisdiction or is simply prescribes rules for how the pending cases may proceed?