The 2010 Patient Protection and Affordable Care Act (ACA) was passed to provide more affordable health coverage to Americans beginning in 2014. Modeled after the 2006 Massachusetts health care reform, the ACA includes an individual mandate, Medicaid expansion, and health exchanges through which middle-income individuals can purchase coverage from private insurance companies. However, while the ACA provisions exclude all undocumented and some documented immigrants, Massachusetts uses state and hospital funds to extend coverage to these groups. This article examines the ACA reform using the Massachusetts reform as a comparative case study to outline how citizenship status influences individuals' coverage options under both policies. The article then briefly discusses other states that provide coverage to ACA-ineligible immigrants and the implications of uneven ACA implementation for immigrants and citizens nationwide.