Chief Justice John Roberts wrote for himself, Justice Anthony Kennedy and the four liberal justices that:

“Congress passed the Affordable Care Act to improve health insurance markets, not to destroy them… If at all possible, we must interpret the Act in a way that is consistent with the former, and avoids the latter.”

Justice Antonin Scalia wrote the dissent, joined by Clarence Thomas and Samuel Alito, suggesting that the health care reform should be called SCOTUScare because the high court has now intervened twice to save the flawed law.

The opinion is available here: http://www.supremecourt.gov/opinions/14pdf/14-114_qol1.pdf