Association for Public Policy Analysis & Management

Introduction. Historically, Medicaid coverage for non-elderly adults with disabilities has been largely contingent on enrollment in the Supplemental Security Income (SSI) program.  The expected cumulative Medicaid expenditures for a disabled adult SSI beneficiary from program entry through the first six years of participation (or death) are more than 4 times that of her SSI cash benefits.  It is thus plausible that the health insurance benefit is more valuable than the cash benefit.  As such, prospective and current SSI enrollees face a strong disincentive to work because earned income or savings beyond the SSI income and asset limits may jeopardize Medicaid coverage in addition to cash benefits.   Recent adult Medicaid expansions increased the paths by which low-income adults with disabilities may obtain or retain health insurance without participating in SSI.

Study Aims.We compare the change in SSI program participation for non-elderly adults that resided in states that implemented a Medicaid expansion for childless adults between 2006 and 2013 to the change in SSI participation in states without a Medicaid coverage expansion. We expect to observe a relative decline in SSI participation rates among non-elderly adults in the states that expanded Medicaid eligibility.

Methods.  Our empirical strategy is a difference-in-differences design that uses the variation in state implementation of childless adult coverage over time, both within and across states, as the exogenous determinant of Medicaid eligibility.  The nationally representative American Community Survey is the primary data source for the study outcome, SSI participation, and for person- and geographic- covariates. We define SSI participation as receipt of any SSI income within the year.  The study’s main independent variable, Medicaid eligibility for childless adults, requires identification of Medicaid waiver and eligibility status in each state-year.  To that end, the project team is constructing a new dataset using extensive documentation from the Center for Medicare and Medicaid Services.   It is well underway and includes the following elements for each state-year: the presence of any Medicaid eligibility for childless adults; the income eligibility criteria; and the use of enrollment caps.

Sample.  The sample includes ACS respondents ages 21-64 in years 2006 through 2013.  The total unweighted sample size is 16,333,974 individuals.

Preliminary Results. The national average percent of the non-elderly adult population receiving benefits from SSI between 2006-2013 ranged from a low of 1.8% (2008) to a high of 3.2% (2011).  SSI benefit receipt likewise varied across states during the study period from 1.5% to 4.8%.

Discussion. This study will yield the first population-based estimates of the effects of decoupling eligibility for Medicaid from SSI for adults with disabilities on SSI participation rates.  Our results will additionally provide insight into the relative value of health insurance coverage and cash benefits for low-income adults with disabilities.  The actions of the “early-expansion” states in this study foreshadow the 2014 implementation of the ACA’s adult Medicaid expansion provision.   Thus, study estimates will be of keen interest to federal policymakers as they anticipate the broader consequences of Medicaid expansions from the Affordable Care Act (ACA) on social welfare programs.