[Excerpt] The Patient Protection and Affordable Care Act (ACA; P.L. 111-148, as amended) expands insurance coverage in the United States through its “shared responsibility” provisions: Employers either provide health coverage or face potential employer tax penalties; likewise, individuals purchase health coverage or face potential individual tax penalties. The ACA does not require employers to provide health coverage, but it does impose employer penalties in the form of a monthly tax on employers that do not provide adequate and affordable health coverage to certain employees. This is known as the employer “shared responsibility” provision. This report describes the potential employer penalties as well as regulations to implement the ACA employer provisions. The regulations address insurance coverage requirements, methodologies for determining whether a worker is considered full time, provisions relating to seasonal workers and corporate franchises, and other reporting requirements. Beginning in 2015, employers employing at least 50 full-time equivalent (FTE) employees are subject to the employer shared responsibility provisions under Section 4908H of the Internal Revenue Code (IRC) as amended by the ACA. However, in 2015 there is transition relief for employers employing between 50 and 100 FTE employees if certain criteria are met. (Additional transition relief is available in certain circumstances as explained in “Implementation and Transition Relief” section of this report.)