HARRISBURG — The requirement in the national health-care overhaul law that individuals buy health insurance is unconstitutional, a federal judge in Pennsylvania ruled Tuesday in a question that the U.S. Supreme Court is expected to settle.

The suit decided by Judge Christopher C. Conner in Harrisburg is one of more than 30 lawsuits nationwide that have been filed over the 2010 law that is President Barack Obama’s signature initiative.

Conner, who was appointed to the federal bench in 2002 by President George W. Bush, said the individual mandate is an unconstitutional extension of authority granted to the federal government under the Constitution’s commerce clause.

“The nation undoubtably faces a health care crisis,” Conner said.

“Scores of individuals are uninsured and the costs to all citizens are measurable and significant. The federal government, however, is one of limited enumerated powers, and Congress’s efforts to remedy the ailing health care and health insurance markets must fit squarely within the boundaries of those powers.”