The Supreme Court heard six hours of arguments March 26 - 28 making it one of the longest sessions in the court's history.
March 26: Technical arguments on a federal law, the Anti-Injunction Act, or AIA. The question is whether a case can come before the court before it is fully implemented and before it has affected commerce.
If the Supreme Court rules that the AIA applies to the health care law then no challenge to the individual mandate can be heard for several years, until penalties for not purchasing insurance come into effect.
March 27: Arguments on the provision of the health care law, called the individual mandate, which requires most people to buy health insurance by 2014 or pay a penalty.
The question is if Congress has the authority to pass a law to regulate economic inactivity - not buying insurance - rather than activity.
March 28 session 1: Arguments on what happens to the healthcare law if the insurance requirement is struck down.
March 28 session 2: The justices will hear arguments on whether states will be forced to spend more on health care for the poor by expanding Medicaid. Starting in 2014, states will be asked to cover individuals under 65 years old with incomes up to 133% of the poverty level.