WASHINGTON — The Supreme Court refused Monday to bypass the lower courts and take up an immediate challenge to the constitutionality of the national health-care reform law and its requirement that all those who can afford it have medical insurance by 2014.

The announcement concerned only the timing of a decision on the health-care law and said nothing about how the court may finally rule. The justices rarely skip over the lower courts before taking up a constitutional question and have said they will do so only if a case is of such “”imperative public importance”” as to “”require immediate determination”” by the high court.

The justices without comment turned down an appeal from Virginia’s attorney general, who insisted the Affordable Care Act has “”roiled America”” and left employers and citizens “”mired in uncertainty.””

The court’s brief order apparently spoke for all the justices, since there was no indication that Justice Elena Kagan had recused herself. Some conservative activists have suggested that Kagan should not take part in the health-care case since she served as U.S. solicitor general before joining the court.

The court’s action almost certainty puts off a ruling on the health-care law until at least next year.

The attorneys general from more than half the states, nearly all of them Republican, filed lawsuits contending the mandate for individuals to have health insurance exceeded Congress’s power to regulate commerce. The main lawsuit was filed in Pensacola, Fla.

But on the day President Obama signed the health-care bill into law, Kenneth Cuccinelli, Virginia’s attorney general, filed a separate suit in Richmond. He won before a federal district judge who declared the mandate to be unconstitutional. The Obama administration, as expected, filed an appeal, and the case is to be heard by the U.S. 4th Circuit Court of Appeals on May 10.

A judge in Florida also declared the law unconstitutional, and an appeal of that decision will be heard by the U.S. 11th Circuit Court of Appeals in Atlanta.

Usually, the losing side appeals, but Cuccinelli nonetheless petitioned the Supreme Court to take up his case before the 4th Circuit Court could rule.

Obama administration lawyers used the opportunity to set out a lengthy defense of the law. They said the market for healthcare services is quite unusual. The need for medical care is “”essentially universal. … Nearly everyone will require health services at some point in his or her lifetime,”” but the need for “”expensive medical care is unpredictable.””

Federal law requires hospitals to provide emergency care for those in need, and in 2008, healthcare providers had to pay $43 billion to cover the cost of those who could not pay. The administration argues that the requirement to have health insurance will spread the costs to all those who can afford to pay.

The administration’s lawyers also argued that Virginia had no standing to sue because the healthcare mandate applies to individuals, not the state.