Justice Roberts wrote the majority opinion, and was joined by justices Ginsberg, Breyer, Sotomayor, and Kagan.
 
On the Role of the Court:

"Members of this Court are vested with the authority to interpret the law; we possess neither the expertise nor the prerogative to make policy judgments. Those decisions are entrusted to our Nation’s elected leaders, who can be thrown out of office if the people disagree with them. It is not our job to protect the people from the consequences of their political choices." (P.6)

On the Individual Mandate:

"Under the mandate, if an individual does not maintain health insurance, the only consequence is that he must make an additional payment to the IRS when he pays his taxes. The mandate can be regarded as establishing a condition – not owning health insurance – that triggers a tax – the required payment to the IRS. Under that theory, the mandate is not a legal command to buy insurance. Rather, it makes going without insurance just another thing the Government taxes, like buying gasoline or earning income. And if the mandate is in effect just a tax hike on certain taxpayers who do not have health insurance, it may be within Congress’s constitutional power to tax." (P.32)
 
"Given its expansive scope, it is no surprise that Congress has employed the commerce power in a wide variety of ways to address the pressing needs of the time. But Congress has never attempted to rely on power to compel individuals not engaged in commerce to purchase an unwanted product. Legislative novelty is not necessarily fatal; there is a first time for everything. But sometimes 'the most telling indication of a severe constitutional problem… is the lack of historical precedent.'" (P. 18)

On the Medicaid Expansion:

"Nothing in our opinion precludes Congress from offering funds under the ACA to expand the availability of health care, and requiring that states accepting such funds comply with the conditions on their use. What Congress is not free to do is to penalize States that choose not to participate in that new program by taking away their existing Medicaid funding." (P. 55)
 
"The legitimacy of Congress’s exercise of the spending power “thus rests on whether the State voluntarily and knowingly accepts the terms of the ‘contract.’” Respecting this limitation is critical to ensuring that Spending Clause legislation does not undermine the status of the States as independent sovereigns in our federal system. That system “rests on what might at first seem a counterintuitive insight, that 'freedom is enhanced by the creation of two governments, not one.’”(P.47)

On Applicability of Anti-Injunction Act:

"It is of course true that the Act describes the payment as a “penalty,” not a “tax.” But while that label is fatal to the application of the Anti-Injunction Act, supra, at 12–13, it does not determine whether the payment may be viewed as an exercise of Congress’s taxing power. It is up to Congress whether to apply the Anti-Injunction Act to any particular statute, so it makes sense to be guided by Congress’s choice of label on that question. That choice does not, however, control whether an exaction is within Congress’s constitutional power to tax." (P.33)

Justice Kennedy authored the dissenting opinion in this case, with Justices Scalia, Thomas, and Alito.

"The Court regards its strained statutory interpretation as judicial modesty. It is not. It amounts instead to a vast judicial overreaching. It creates a debilitated, inoperable version of health-care regulation that Congress did not enact and the public does not expect. It makes enactment of sensible health-care regulation more difficult, since Congress cannot start afresh but must take as its point of departure a jumble of now senseless provisions, provisions that certain interests favored under the Court’s new design will struggle to retain. And it leaves the public and the States to expend vast sums of money on requirements that may or may not survive the necessary congressional revision." (P.64)
 
"Against the mountain of evidence that the minimum coverage requirement is what the statute calls it—a requirement—and that the penalty for its violation is what the statute calls it—a penalty—the Government brings forward the flimsiest of indications to the contrary." (P. 22)