Writing for the Court, Chief Justice John Roberts presided over a splintered opinion covering three primary issues. On the first issue, the ability for the Court to even hear the case, Roberts explained that since Congress chose to describe the shared responsibility payment as a “penalty” instead of a “tax”, “[t]here is no immediate reason to think that a statute applying to ‘any tax’ would apply to a “penalty.” Therefore, the Court was permitted to proceed to the merits of the case.

On the constitutionality of the individual mandate, Roberts first stated that the individual mandate couldn’t be justified under the Commerce Clause because the power to regulate commerce “presupposes the existence of commercial activity to be regulated.” He explained, “[c]onstruing the Commerce Clause to permit Congress to regulate individuals precisely because they are doing nothing would open a new and potentially vast domain to congressional authority.” Such an authority would allow the government to “justify a mandatory purchase to solve almost any problem”, which Roberts argued is a slippery slope. Further, Roberts found that the Necessary and Proper Clause couldn’t justify the mandate, writing that the Court’s precedent upholding laws under the Clause “involved exercises of authority derivative of, and in service to, a granted power. The individual mandate, by contrast, vests Congress with the extraordinary ability to create the necessary predicate to the exercise of an enumerated power.”

Roberts then addressed whether the individual mandate could be upheld under the Taxing and Spending Clause, finding that it could. Roberts first established that the Court’s task isn’t to determine if the individual mandate is most naturally interpreted as a tax, only whether its a “fairly possible” one. Roberts explained that the individual mandate looks like a tax in “many respects”, but most importantly that the process it implements “yields the essential feature of any tax: it produces at least some revenue for the Government.” He also explained that taxes that seek to influence conduct are not new to the country, and pointed to some of the earliest federal taxes that were enacted to deter the purchase of imported goods. Roberts addressed the contradiction between this finding and the Court’s finding on the Tax Anti-Injunction Act, stating that the “penalty” label is fatal to the application of the Act because it’s “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.” Roberts concluded his discussion of the individual mandate, writing “[t]he Federal Government does not have the power to order people to buy health insurance… The Federal Government does have the power to impose a tax on those without health insurance.”

Moving on to Congress attempt to expand Medicaid by threatening to withhold all Medicaid funding from states who didn’t comply with new requirements, Roberts found that Congress had overstepped their constitutional authority. Roberts argued that allowing the federal government to force the implementation of federal programs would threaten political accountability key to our federal system, since state officials would face public opinion for carrying out plans created by federal officials. Roberts explained that Spending Clause programs are permitted when they offer a State a legitimate choice to accept the conditions and funding, because state officials can be properly held accountable for the decision to accept. However, Roberts wrote that when the conditions imposed are more akin to threats to terminate other independent grants, they can be properly viewed as “a means of pressuring the States to accept policy changes.” He found that in this case, Congress’ threats were a “gun to the head.” Roberts rejected the government’s argument that they were merely tweaking a program the States had already agreed to rather than forcing them to accept a radically different version of it. He explained that the Medicaid expansion is a shift in “kind, not merely degree” and that under the new law, Medicaid “is no longer a program to care for the neediest among us, but rather an element of a comprehensive national plan to provide universal health insurance coverage.”

Roberts concluded that the Affordable Care Act was both constitutional and unconstitutional in part, but emphasized the Court’s deference to the legislative branch on matters of policy. Thus, the portions of the Act found unconstitutional were deemed severable, and the rest was upheld.