The Subcommittee on Oversight of the Committee on Ways and Means has reviewed the implementation of the tax and tax-related revenue provisions of the Patient Protection and Affordable Care Act (ACA). The Affordable Care Act has made broad-based changes to the law with respect to health insurance coverage in the individual and group markets and the law with respect to group health plans as well as laws that apply to Medicare and Medicaid. The ACA also includes a significant number of changes to the Code, including the addition of new Code sections and the amendment of previously existing Code sections. The ACA also includes off-Code revenue provisions that impose certain industry fees. This book provides a summary of health insurance changes made by the ACA and a description of the present law rules with respect to ACA revenue provisions and their implementation.