The Patient Protection and Affordable Care Act (ACA) included new eligibility and enrollment requirements, which have presented states with significant implementation opportunities and challenges. Although states had choices about whether to host a health insurance exchange or expand Medicaid, the ACA required all states to make major changes to Medicaid eligibility policy, including adding mandatory coverage of new groups, implementing streamlined eligibility and renewal processes, incorporating new eligibility and verification requirements, and coordinating enrollment systems with exchanges.