The Patient Protection and Affordable Care Act, or ACA (sometimes colloquially referred to as Obamacare), is a major healthcare reform law passed in 2010 by Barack Obama, aimed at providing more comprehensive health insurance options for Americans. Prior to its passage, there were almost 50 million uninsured Americans, 91% of whom were earning less than 400% of the Federal Poverty Line (FPL).

The ACA was designed to increase the availability of affordable insurance options, which it did through two main mechanisms: the expansion of Medicaid and the creation of healthcare marketplaces (exchanges) where individuals could purchase insurance. It also enacted many other smaller measures, both pertaining to and separate from insurance coverage goals (e.g., authorizing the FDA to approve biosimilars, the analogue of a small-molecule generic for biologic drugs). Additionally, it ensured numerous new patient protections, preventing insurers from denying coverage, charging higher premiums, or excluding benefits to individuals with pre-existing conditions who wished to purchase insurance. 

Notably, the ACA was built on top of existing infrastructure; as a result, many of the system’s underlying complexities were not only preserved but, in some cases, intensified. With the expiration of subsidy rates set by the American Rescue Plan Act and the Inflation Reduction Act, it is ever more important to understand exactly where the ACA stands, and the direction in which it is headed. This article aims to break down the evolution and operation of structures established by the ACA, so as to better ground our present policy debates.