Although the Affordable Care Act (ACA) of 2010 directed the expansion of Medicaid to cover all adults with incomes up to 138% of the Federal Poverty Level (FPL), a subsequent Supreme Court ruling in 2012 made this expansion optional. Thus far, 37 states have expanded their programs. This analysis estimates the impact of an expansion of Medicaid in Missouri on the state budget. The full report outlines the important background, sources of data, methods, and assumptions used to generate these estimates. The “best estimate” of the impact on the state budget is presented, along with some sensitivity analysis to show the impact of crucial assumptions on the estimate. There are about 18-20 assumptions made in creating this analysis for 2020, but several of them are quite minor, and most of them have very little impact on the state’s overall financial obligation. The most influential assumptions are highlighted and discussed in the full report.