The Texas Attorney General's office is making arguments Tuesday in a bid to overturn the Affordable Care Act.
Texas and 19 other states sued the federal government in 2018, arguing the measure is unconstitutional.
The lawsuit says Congress made the entire law unconstitutional by setting the penalty for not having insurance at $0.
The U.S. Supreme Court took up the Affordable Care Act in 2012. In the majority opinion, Chief Justice John Roberts wrote the individual mandate amounts to a tax for people who do not have health care.
"He basically said the reason the entire law is constitutional is because Congress has the power to tax," says legal analyst Thane Rosenbaum. "Chief Justice Roberts said, 'I'm not getting into the merits of whether it's a good idea to force people to get health insurance. All I care about is whether the government has a right to tax you.'"
Texas Attorney General Ken Paxton has argued that since the penalty was set at $0, the individual mandate can no longer be considered a tax, and the entire law is unconstitutional.
"If you cut one piece out of the law, does the whole thing topple down, or can you save it? Does it survive?" Rosenbaum asks.
In 2019, about 20 million people had insurance through the Affordable Care Act. Rosenbaum says the Supreme Court may address parts of the law, but he says the court is unlikely to nullify the entire measure because so many people would be affected.
"Supreme Courts don't like to cause chaos, and that's what could happen here," he says.
Rosenbaum says the court may not issue a decision until next June.