The court’s decision means the issue will continue working its way through the federal appeals courts. Several cases are pending, including challenges to the law from Virginia, Florida, and 25 other states.

They claim that the centerpiece of the law — requiring virtually all Americans to buy health insurance — is unconstitutional. Two federal judges, in Virginia and Florida, have agreed with the states.

Three other judges, also in Virginia and in Michigan and Washington, DC, have found the law constitutional.