Here's the full text (pdf) of the 193-page Supreme Court's ruling on the Affordable Care Act.
Below are some excerpts:
The Court rejects the Commerce Clause argument:
CHIEF JUSTICE ROBERTS concluded in Part III–A that the individual mandate is not a valid exercise of Congress’s power under the Commerce Clause and the Necessary and Proper Clause. Pp. 16–30.The Court upholds Obamacare on the Tax argument:
Construing 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. Congress already possesses expansive power to regulate what people do. Upholding the Affordable Care Act under the Commerce Clause would give Congress the same license to regulate what people do not do. The Framers knew the difference between doing something and doing nothing. They gave Congress the power to regulate commerce, not to compel it. Ignoring that distinction would undermine the principle that the Federal Government is a government of limited andenumerated powers. The individual mandate thus cannot be sustained under Congress’s power to “regulate Commerce.” Pp. 16–27.
The most straightforward reading of the individual mandate is that it commands individuals to purchase insurance. But, for the reasons explained, the Commerce Clause does not give Congress that power. It is therefore necessary to turn to the Government’s alternative argument: that the mandate may be upheld as within Congress’s power to “lay and collect Taxes.”
The Court rules the Feds cannot not punish states by withholding existing Medicaid funding:
Section 1396c gives the Secretary of Health and Human Services the authority to penalize States that choose not to participate inthe Medicaid expansion by taking away their existing Medicaid funding. 42 U. S. C. §1396c. The threatened loss of over 10 percent of a State’s overall budget is economic dragooning that leaves the States with no real option but to acquiesce in the Medicaid expansion. The Government claims that the expansion is properly viewed as only a modification of the existing program, and that this modification impermissible because Congress reserved the “right to alter, amend, or repeal any provision” of Medicaid. §1304. But the expansion accomplishes a shift in kind, not merely degree. The original program was designed to cover medical services for particular categories of vulnerable individuals. Under the Affordable Care Act, Medicaid is transformed into a program to meet the health care needs of the entire nonelderly population with income below 133 percent of the poverty level. A State could hardly anticipate that Congress’s reservation of the right to “alter” or “amend” the Medicaid program included the power to transform it so dramatically. The Medicaid expansion thus violates the Constitution by threatening States with the loss of their existing Medicaid funding if they decline to comply with the expansion. Pp. 51–55.
The Tax argument, SCALIA, KENNEDY, THOMAS, and ALITO, JJ., dissenting: The mandate is not a "tax."
That §5000A imposes not a simple tax but a mandate to which a penalty is attached is demonstrated by the fact that some are exempt from the tax who are not exempt from the mandate—a distinction that would make no sense if the mandate were not a mandate. Section 5000A(d) exempts three classes of people from the definition of “applicable individual” subject to the minimum coverage requirement: Those with religious objections or who participate in a “health care sharing ministry,”§5000A(d)(2); those who are “not lawfully present” in the United States, §5000A(d)(3); and those who are incarcerated, §5000A(d)(4). Section 5000A(e) then creates a separate set of exemptions, excusing from liability for the penalty certain individuals who are subject to the minimum coverage requirement: Those who cannot afford coverage, §5000A(e)(1); who earn too little income to require filing a tax return, §5000A(e)(2); who are members of an Indian tribe, §5000A(e)(3); who experience only short gaps in coverage, §5000A(e)(4); and who, in the judgment of the Secretary of Health and Human Services, “have suffered a hardship with respect to the capability to obtain coverage,” §5000A(e)(5). If §5000A were a tax, these two classes of exemption would make no sense; there being no requirement, all the exemptions would attach to the penalty (renamed tax) alone.