Federal statute and regulations mandate coverage of certain populations and benefits and define optional populations and services that states may cover in their Medicaid programs. States design their programs within federal requirements to meet specific needs and priorities. In this session, we presented our analysis of enrollment and spending for mandatory and optional enrollees and services using data from the Transformed Medicaid Statistical Information System (T-MSIS) and the CMS-64 net financial management report for fiscal year 2023.