The American Rescue Plan Act of 2021 (ARPA, P.L. 117-2), through a temporary increase in the federal medical assistance percentage, provided state Medicaid programs with $37.1 billion in one-time funding for state-driven home- and community-based services (HCBS) reinvestment activities. Since ARPA’s enactment, MACPAC has been monitoring state efforts to spend the funds and is working to understand state experiences with implementation, particularly given the size of the investment and the compressed timeline states had in which to spend it. This session provided a legislative summary of ARPA and background on timelines and guidance associated with its implementation, as well as key takeaways from MACPAC’s monitoring efforts related to timing, program evaluation, and sustainability.