State-by-State Estimates of Reductions in Federal Medicaid Funding Under Repeal of the ACA Medicaid Expansion

2016 Base.  We generated estimates of Medicaid enrollment and spending for expansion enrollees in FY2016 based on Kaiser Family Foundation analysis of the FY2015 MSIS. We adjusted MSIS spending to CMS-64 spending to account for MSIS undercounts of spending. Because FY2015 MSIS data was missing some or all quarters for some states, we also adjusted the enrollment data using secondary data to represent a full fiscal year of enrollment. We accounted for a state’s expansion status, the number of quarters of missing data, and the state’s historical patterns of spending and enrollment in making state-by-state adjustments, using similar methods we used for estimates for earlier years. Because MSIS does not identify adults who are eligible through the ACA expansion versus pre-ACA pathways, we used the FY2015 MBES data to break out enrollment and spending for Group VIII (ACA expansion) enrollees. We then inflated to FY2016 based on the OACT estimates of annual changes in enrollment and spending by eligibility group, with the exception of enrollment for Group VIII, which was obtained from the available FY2016 MBES data. In some cases (e.g., states that expanded after FY2015), we made state-specific adjustments to the data.

Baseline Projections.  We used the FY2016 base year data to project future Medicaid enrollment and spending. Because there is uncertainty around future growth rates in Medicaid and estimates vary widely, we used the average of OACT and CBO predictions of future growth in Medicaid enrollment and spending per enrollee by eligibility group. We applied the same growth rates to all states. We calculated the federal/state split in spending by enrollment group for each year based on the relevant FMAP for the eligibility group and year. For non-expansion groups, we used the most recent FMAPs available (FY2018) for all years; for expansion groups, we used the FMAPs for each year as specified under current law, though we did not account for differential match rates for Group VIII enrollees who are not newly eligible and may qualify for a different match rate. Since these projections use national data and uniform growth rates, state individual state estimates may have more detailed data.

ACA Repeal.  For purposes or repealing the ACA, we assume all spending and coverage in the expansion group (Group VIII) are eliminated starting in 2020.  These estimates do not assume that states make other changes to maintain this coverage (even for states that had waiver coverage prior to the ACA).