According to Reuters:
"The Affordable Care Act's requirement that certain individuals pay a financial penalty for not obtaining health insurance may reasonably be characterized as a tax," Chief Justice John Roberts wrote for the court's majority in the opinion.
"Because the Constitution permits such a tax, it is not our role to forbid it, or to pass upon its wisdom or fairness," he concluded.
It's bad enough that the U.S. government claims the power to tax, but it adds insult to injury for the Court to claim that a fine for not doing something is a tax. Idiotic.