(CNN) -- A federal appeals court in Cincinnati expressed concern Wednesday over the sweeping health care reform law championed by President Barack Obama, especially the requirement that Americans purchase health insurance in coming years or face financial penalties.
The case could turn on either a broad reading of congressional power to regulate the health insurance market, or more mundane procedural issues. It is one of 30-some legal challenges nationwide to the health care reform effort, an issue that is certain to ultimately reach the Supreme Court, perhaps by year's end.
The three-judge panel of the U.S. Court of Appeals for the 6th Circuit heard 90 minutes of oral arguments Wednesday over the constitutionality of the Patient Protection and Affordable Care Act, passed by the Democratic Congress last year.
Judge Jeffrey Sutton questioned whether consumers could be forced to purchase something like health insurance that they may neither want nor need.
"It is just not proper to make people buy things, that's the point," said Sutton, appointed to the bench by President George W. Bush. Judge James Graham -- a Reagan appointee -- also worried if Congress is exceeding its authority under the Constitution's commerce and spending clauses.
The third judge, Boyce Martin -- who is considered a liberal and was named by President Carter -- did not press Justice Department lawyers especially hard on the constitutional questions.
But all three jurists in the crowded courtroom asked tough questions of the plaintiffs, suggesting all Americans at some point would need medical care, and that choosing to stay out of the health care market may not be practical if the goal is to control costs and maintain quality of care.
Various state and private challenges to the law are now before federal appeals courts across the United States. Another provision mandates expansion of Medicaid, the low-income health program administered by the states.
The high court could be asked this fall to take formal jurisdiction over one or more health care appeals, and it could decide the matter perhaps by 2012, a presidential election year.
A sticking point that could nullify this appeal may involve "standing." The Obama administration urged the 6th Circuit to dismiss the case because it was recently revealed one of the plaintiffs had purchased health insurance from her employer. The first part of Wednesday's arguments addressed this "standing" issue.
Acting Solicitor General Neal Katyal argued that since Jann DeMars of Michigan already has such insurance, she lacks the right to claim any harm from the "individual mandate" provision requiring the purchase of health insurance by 2014.
Her lawyers from the Thomas More Law Center -- a conservative legal advocacy group -- countered the insurance DeMars currently has would not cover all the medical services that would be required under the new law.
The judges now have the option of dismissing the appeal on this "gateway" question without ruling on the broader substantive merits of the case.
The issue could ultimately turn on whether forgoing medical insurance or coverage represents economic "activity," an area long considered proper for congressional oversight in interstate commerce. Opponents, including more than two dozen states, argue it is not.
The Justice Department countered that since every American will need medical care at some point in their lives, individuals do not "choose" to participate in the health care market. Federal officials cite 2008 figures of $43 billion in uncompensated costs from the millions of uninsured people who receive health services, costs that are shifted to insurance companies and passed on to consumers.
The four individual plaintiffs from Michigan say the government has no business interfering with their individual health care decisions.
The 6th Circuit panel gave no clear indication how it will rule on these key questions.
Its ruling would technically affect only those states covered by the 6th Circuit: Michigan, Ohio, Kentucky, and Tennessee. But it would help set the tone for other courts considering similar issues.
Next week, a federal appeals court in Atlanta will hear arguments in a lawsuit filed by Florida and 25 other states over the law. An appeals court in Richmond heard two separate challenges last month.
One pressing concern is whether parts of the law already in effect can continue to be enforced. Those sections currently being administered include small business tax credits, federal grants and consumer protection measures. The federal government wants to know whether these provisions can continue while the issue is under appeal, particularly in the 28 states that have filed suit.
Other questions that could prompt a high court review include:
-- If one provision of the law is found unconstitutional, does the entire act become invalidated?
-- Should employers be forced to provide some level of health insurance to their workers?
-- Can religious, moral, and other objections to the law be considered?
-- Do states and private groups have "standing," or legal authority to bring their claims, or is congressional taxing authority ultimately exempt from such lawsuits?
Oklahoma and a range of private groups have also filed separate legal challenges that are concurrently working their way through federal courts around the country.
The Affordable Care Act has about 450 components, placing a number of new or revised regulations on states, private insurance companies, employers and individuals.
Federal judges in Florida and Virginia in recent months found parts of the law unconstitutional, while colleagues in Michigan and Virginia upheld the provisions.
Health care reform, a top Democratic priority since the Truman administration, was passed by the last Congress in a series of virtually party-line votes. Obama signed the act into law in March 2010. The law is widely considered to be the signature legislative accomplishment of the president's first two years in office.
Among other things, the measure was designed to help millions of uninsured and underinsured Americans receive adequate and affordable health care through a series of government-imposed mandates and subsidies. The federal government stated in court briefs that 45 million Americans last year were without health insurance, roughly 15 percent of the country's population.
Critics have equated the measure to socialized medicine, fearing a bloated government bureaucracy will result in higher taxes and diminished health care services. About two dozen challenges have been filed in federal courts nationwide.
Opponents derisively labeled the measure "Obamacare." Republican leaders, who captured the House of Representatives in the midterm elections, have vowed to overturn or severely trim the law.
The case argued Wednesday is Thomas More Law Center v. Obama (10-2388). A ruling is expected within a few months.