In previous cases, the 6th Circuit Court of Appeals in Cincinnati and the D.C. Circuit Court of Appeals in Washington upheld the individual mandate. But the courts have not ruled in lockstep. The 11th Circuit in Atlanta found the mandate unconstitutional but allowed the rest of the law, including the Medicaid expansion, to stand.
Last November, the U.S. Supreme Court agreed to hear arguments from two 11th Circuit cases filed by the National Federation of Independent Business and a 26-state coalition led by the State of Florida.
In March, the high court heard oral arguments on the Medicaid expansion and the individual mandate as well as the mandate's severability from the rest of the law. It also considered whether the fine for not buying insurance is a "penalty" or a "tax." That distinction is important because federal law bars the court from ruling on a tax dispute before the tax is levied.
Predicting the outcome
Constitutional law experts who followed proceedings in the case believe that Justice Anthony Kennedy, a moderate Reagan-era appointee, may hold the deciding vote. On Day 2 of oral arguments in March, Kennedy said the federal government has "a heavy burden" to justify Congress' right to mandate health insurance coverage. Yet he also seemed to acknowledge the government's view that health insurance is different from other markets.Chief Justice John Roberts, another Republican appointee, also posed questions that seemed to both bolster and undercut the government's position.
"I think that there's a strong possibility that the court will uphold the entire law, 6 to 3, with Kennedy and Roberts voting to uphold it," said law professor Renée Landers, director of Suffolk University Law School's Health and Biomedical Law Concentration, in Boston.
She found both justices' questions "quite balanced" and believes "both of them have this institutional concern for the court about wiping out in one fell swoop 70-plus years of jurisprudence on the Commerce Clause," the section of the Constitution that gives Congress the power to regulate activities that affect interstate commerce.
"If the law is invalidated in any respect, it'll be a 5-4 decision, clearly along Republican-appointee, Democratic-appointee lines," Landers added.
At Intrade, an online financial exchange for wagering on political, entertainment and financial events, investors have been predicting the individual mandate has a better than 57 percent chance of being ruled unconstitutional by the court before year's end, and a 61 percent chance of its demise before the end of 2013.
George Mason's Somin doesn't believe the federal government's arguments in defense of the mandate stand up to scrutiny. "When you look at each one of them closely, they all break down against inspection," he said.
What it means for patient care
Striking down the health reform law would end health insurance coverage for millions of Americans, disrupt efforts to improve care coordination and halt important insurance market reforms, among other reforms, according to the American Medical Association.
"We continue to support the health reform law as an important step in transforming our health-care system, although we are working hard to improve and make important changes in the law," AMA President-elect Dr. Jeremy Lazarus said in a prepared statement.
Added Michael Miller, policy director at Boston-based Community Catalyst, a national consumer advocacy group: "The implications for patients . . . and for the health-care system are catastrophic."
Miller cited a Robert Wood Johnson Foundation-funded study published in the journal Medical Care that suggested that high rates of "uninsurance" in a community have a "spillover effect," negatively influencing working-age adults' and seniors' access to health-care services and satisfaction with the care they receive.
A majority of working-age adults and children in America -- 53.5 percent in 2010, according to a study by the National Institute for Health Care Reform -- have coverage through an employer-sponsored health plan.