The battle was far from over. In 2011, 26 states, a number of individuals and the National Federation of Independent Business sued in federal district court over the constitutionality of two major aspects of the ACA: the individual mandate, which requires nonexempt Americans to buy health insurance or pay a penalty, and the Medicaid expansion, which states must accept or face a cutoff of federal contributions to their Medicaid programs.
In 2012, the U.S. Supreme Court heard the case of National Federation of Independent Business v. Sebelius. In a narrow decision, the court upheld the individual mandate, but not for the reasons the administration argued. According to the justices, the requirement was not valid under the Commerce Clause and the Necessary and Proper Clause, but rather was a reasonable application of the Taxing Clause. As for Medicaid expansion, the majority held that Congress could not hold Medicaid funding hostage to ensure compliance, and that states could continue to receive funding whether they participated in the expansion or not. Nonparticipation would now merely mean that they would not receive extra funding [sources: Liptak; Smith; U.S. Supreme Court].
Although some elements of the ACA went into effect immediately, the law properly went into force in 2014. In response, 14 states and the District of Columbia opted to create self-run marketplaces, while the remaining states worked with, or ceded responsibility to, the federal government. The first open enrollment kicked off on March 31, 2014. Despite a rocky launch for insurance exchange portal Healthcare.gov, it ended with 8 million enrollees, outpacing Congressional Budget Office forecasts [source: Blumenthal and Collins]. The next round of open enrollment runs from Nov. 15, 2014, through Feb. 15, 2015 [source: Sanger-Katz].
Meanwhile, the political and legal struggle over health care reform continues. Between assuming control of the House in 2011 and the fourth anniversary of the signing in 2014, Republicans have voted 54 times to repeal, overhaul or fiddle with the ACA [source: O'Keefe]. The Supreme Court will hear petitions to review its ruling in 2015, this time potentially examining the constitutionality of federal government subsidies paid to states that depend on the federal insurance exchange. Because such subsidies are essential to the success of the ACA, the future of health care reform could hinge on the court's interpretation of a few brief words [source: Pear].