The case of King v Burwell refocused attention on the different paths states followed to implement the Affordable Care Act (ACA). The ACA includes 3 distinct approaches to organizing health insurance marketplaces. Fourteen states and the District of Columbia established state-based marketplaces (SBMs) that allow states to design and operate online insurance marketplaces, certify qualified health plans, and assist consumers through outreach and educational efforts. Seven states adopted state partnership marketplaces (SPMs) that delegate operation of the online website to federal officials, while retaining control over plan management, consumer assistance programs, or both. Twenty-nine states opted for federally facilitated marketplaces (FFMs), for which federal officials perform plan management and consumer assistance services and also operate the online marketplace.