Understanding Participation in SSI

Published: 2015


The Supplemental Security Income program (SSI) provides a guaranteed income for the elderly. As such it can serve to mitigate any deleterious effects of reductions in Social Security benefits that might result from any Social Security reform. However, participation in SSI among qualified individuals has proven to be low. We show that this low participation rate, just over 50%, observed at the program’s inception has continued to today with little if any change. We also find that transfers from children are far larger among eligible non-participants suggesting that family assistance may offset the need for public assistance.

Key Findings

    • Discussions of potential changes frequently include increases in the normal retirement age and changes to the Consumer Price Index—both of which will reduce benefits. These benefit reductions are likely to have significant implications for the well-being of low-income elderly who depend heavily on Social Security.
    • There remains a subset of elderly with incomes below the poverty line, and many of these individuals are not enrolled in the SSI program. Here we begin to examine the relationship between family and public assistance.
    • While we find some evidence of substitution between sources of assistance, it is small.
    • We are currently augmenting our study with additional years of data and a more complete accounting of state benefits.


McGarry, Kathleen, and Robert F. Schoeni. 2015. “Understanding Participation in SSI.” University of Michigan Retirement Research Center (MRRC) Working Paper, WP 2015-319. Ann Arbor, MI. https://mrdrc.isr.umich.edu/publications/papers/pdf/wp319.pdf