The Obama Administration faces what will likely be the deciding court challenge to his 2010 health care law as 26 states and a business group seek to strike down the entire law in a Supreme Court appeal.

In its appeal to the high court on Wednesday to decide on the case, the Administration pointed to the key point in a lower court in which it lost. Experts believe the court may take up the case later this year and render a decision by June of 2012.

The first is whether Congress had the power under the Constitution to require virtually everyone in the U.S. to buy health insurance starting in 2014. A federal court in Atlanta ruled that the core of the law passed in 2010, the individual mandate requiring insurance had violated the law.

The Department of Health and Human Services, which is working to implement the law, and filed the appeal, suggested that the Supreme Court ask the states and the National Federation of Independent Business “whether the suit brought by the respondents to challenge the minimum coverage provision of the Patient Protection and Affordable Care act is barred by the Anti-Injunction Act, 26 U.S.C 7421(a).

Meanwhile, the 26 States and National Federation of Independent Businesses are asking the court to determine if the entire law should be blocked, not only the core requirement to purchase insurance.

“[D]espite the fact that the mandate is a ‘requirement’ that Congress itself deemed ‘essential’ to the Act’s new insurance regulations … the Eleventh Circuit held that the mandate is severable from the remainder of the Act,” the States and NFIB wrote in their petition.

“The question presented is whether the ACA must be invalidated in its entirey because it is non-severable from the individual mandate that exceeds Congress’ limited and enumerated powers under the Constitution.”