WASHINGTON — A conservative-leaning appeals court panel on Tuesday upheld the constitutionality of President Barack Obama’s health care law, as the Supreme Court prepares to consider this week whether to resolve conflicting rulings over the law’s requirement that all Americans buy health care insurance.

A panel of the U.S. Court of Appeals for the District of Columbia issued a split opinion upholding the lower court’s ruling that found Congress did not overstep its authority in requiring people to have insurance or pay a penalty on their taxes, beginning in 2014.