Affordable Care Act

The Individual Mandate
26 USC 5000A - Requirement to maintain minimum essential coverage

State of Florida v. U.S. Department of Health & Human Services - 11th Circuit - individual mandate exceeds Congress's power under commerce clause (dissent by Stanley Marcus)

Comonwealth of Virginia v. Sebelius - 4th Circuit - dismissal for lack of standing
New Jersey Physicians, Inc. v. President of the United States - 3rd Circuit -dismissal for lack of standing

Liberty University v. Geithner, 4th Circuit, -  pre-enforcement action seeking to restrain the assessment of a tax dismissed under the Anti-Injunction Act