Signed into law on March 23, 2010, the ACA makes notable improvements to Medicaid and the Children’s Health Insurance Program (CHIP) and ensures that millions of Americans will soon have ACA Foster Careaccess to affordable health coverage through Insurance Exchanges. Among the provisions that will take effect in 2014, the law includes several new requirements that are critical for foster children and other vulnerable youth. Most notably, it expands Medicaid coverage to former foster children up to age 26. On January 14, the Centers for Medicare and Medicaid Services (CMS) released a proposed rule that outlines a structure and options for coordinating Medicaid, CHIP and the Exchange. The proposed rule clarifies a number of important provisions with respect to Medicaid eligibility and administration that are relevant for children in out-of-home placement and youth who have “aged-out” of foster care. This brief focuses on CMS’ interpretation of Medicaid eligibility for former foster children under ACA Section 2004.