Verrilli was quick to point out that the nature of the argument Tuesday is different.
"Today we are construing statutory text where the precise choice of words does have a dispositive effect on the analysis," he said. "Tomorrow the question is whether Congress has the authority under the taxing power to enact it and the form of words doesn't have a dispositive effect on that analysis."
Gregory G. Katsas argued on behalf of the 26 states as well as the National Federation of Independent Business, and four individuals challenging the law. He said he is challenging the mandate, not the penalty provision of the law and that the AIA should not block the challenge.
"The purpose of this lawsuit is to challenge a requirement -- a federal requirement to buy health insurance. That requirement is not a tax," he said. "And for that reason alone, we think the Anti-Injunction Act doesn't apply."
Chief Justice John Roberts dismissed a differentiation between the mandate and the penalty.
"The idea that the mandate is something separate from whether you want to call it a penalty or tax just doesn't seem to make much sense," he said.
While most of the attention to the health care debate has centered on the law's individual mandate and its expansion of Medicaid, tax experts are keenly interested in how the court will address the Anti-Injunction Act. They are particularly interested in the government's position that the AIA shouldn't apply to the health care law.
George A. Hani, a tax law expert at Miller & Chevalier, says that if the government wins its argument that the AIA shouldn't apply in this case it could bring more challenges to other tax laws that previously were believed to be barred by the AIA.
"If the government wins on its AIA argument, tax practitioners will seize the language with the eye toward bringing additional challenges to the tax law which previously were believed could only be brought after assessment and collection," he said.