Justice Roberts delivered the opinion of the U.S. Supreme Court yesterday in King v. Burwell. In a 6 to 3 decision, the Court upheld an interpretation of the Affordable Care Act which permits premium tax credits for individuals purchasing health insurance through a federally-operated health benefit exchange.

The opinion states: “Petitioners’ arguments about the plain meaning of Section 36B are strong. But while the meaning of the phrase ‘an Exchange established by the State under [42 U.S. C. §18031]’ may seem plain ‘when viewed in isolation,’ such a reading turns out to be ‘untenable in light of [the statute] as a whole.’ Department of Revenue of Ore. v. ACF Industries, Inc., 510 U. S. 332, 343 (1994). In this instance, the context and structure of the Act compel us to depart from what would otherwise be the most natural reading of the pertinent statutory phrase.”

The Court held that the “credits are necessary for the Federal Exchanges to function like their State Exchange counterparts, and to avoid the type of calamitous result that Congress plainly meant to avoid.”