The Patient Protection and Affordable Care Act (ACA) included new optional Medicaid home and communitybased (HCBS) initiatives: the Balancing Incentive Program, the 1915(k) Community First Choice personal care benefit, and the revised 1915(i) state plan benefit. This study identifies political, economic, programmatic, and intergovernmental factors that facilitated or impeded state participation in these ACA programs. Longitudinal and cross-sectional regression analyses were used to model state adoption from 2011 to 2015. Findings indicate that political ideology, economic factors, and existing HCBS policies were the most important determinants of whether a state adopted the ACA's HCBS opportunities. This research has implications for federal officials interested in spurring states to achieve greater rebalancing of Medicaid long-term services and supports toward HCBS.