Medicare, Medicaid, and dual enrollment for adults with intellectual and developmental disabilities

Health Serv Res. 2024 Jun;59(3):e14287. doi: 10.1111/1475-6773.14287. Epub 2024 Jan 24.


Objective: Given high rates of un- and underemployment among disabled people, adults with intellectual and developmental disabilities rely on Medicaid, Medicare, or both to pay for healthcare. Many disabled adults are Medicare eligible before the age of 65 but little is known as to why some receive Medicare services while others do not. We described the duration of Medicare enrollment for adults with intellectual and developmental disabilities in 2019 and then compared demographics by enrollment type (Medicare-only, Medicaid-only, dual-enrolled). Additionally, we examined the percent in each enrollment type by state, and differences in enrollment type for those with Down syndrome.

Data sources and study setting: 2019 Medicare and Medicaid claims data for all adults (≥18 years) in the US with claim codes for intellectual disability, Down syndrome, or autism at any time between 2011 and 2019.

Study design: Administrative claims cohort.

Data collection and abstraction methods: Data were from the Transformed Medicaid Statistical Information System Analytic Files and Medicare Beneficiary Summary files.

Principle findings: In 2019, Medicare insured 582,868 adults with identified intellectual disability, autism, or Down syndrome. Of 582,868 Medicare beneficiaries, 149,172 were Medicare only and 433,396 were dual-enrolled. Most Medicare enrollees were enrolled as child dependents (61.5%) Medicaid-only enrollees (N = 819,256) were less likely to be white non-Hispanic (58.5% white non-Hispanic vs. 72.9% white non-Hispanic in dual-enrolled), more likely to be Hispanic (19.6% Hispanic vs. 9.2% Hispanic in dual-enrolled) and were younger (mean 34.2 years vs. 50.5 years dual-enrolled).

Conclusion: There is heterogeneity in public insurance enrollment which is associated with state and disability type. Action is needed to ensure all are insured in the program that works for their healthcare needs.

Keywords: Medicaid; Medicare; disability; dual enrollment; intellectual and developmental disability.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Aged
  • Developmental Disabilities*
  • Disabled Persons / statistics & numerical data
  • Down Syndrome
  • Eligibility Determination
  • Female
  • Humans
  • Insurance Claim Review
  • Intellectual Disability*
  • Male
  • Medicaid* / statistics & numerical data
  • Medicare* / statistics & numerical data
  • Middle Aged
  • United States
  • Young Adult