In a court case filed by Texas and 19 other states, the Justice Department said in a brief on Thursday that the requirement for people to have insurance — the individual mandate — was unconstitutional.
If that argument is accepted by the federal court, it could eviscerate major parts of the Affordable Care Act that remain in place.
A definitive court ruling could be months away and appeals of any decision could take many more months, during which the law is likely to stay in effect.