Rupp and Riley 2012 — Longitudinal Patterns of Medicaid and Medicare Coverage Among Disability Cash Benefit Awardees

Summary

First study to link individual-level administrative records from all four major U.S. disability safety-net programs — Disability Insurance (DI), Supplemental Security Income (SSI), Medicare, and Medicaid — in a unified analytic framework. Using N=68,798 first-ever disability entrants in 2000 followed 84 months, the authors document how longitudinal benefit eligibility patterns determine access to and timing of public health insurance (HI). SSI plays a critical bridging role during the 29-month combined DI/Medicare waiting period; once Medicare kicks in for DI recipients, public HI coverage is virtually complete.

Key Claims

• SSI involvement is the overwhelmingly dominant predictor of Medicaid coverage during the first 24 months after disability award; SSI-only group's Medicaid odds ratio vs. DI-only is 37.2× at month +3 and 50.5× at month +24 after controlling for demographics, diagnosis, and state fixed effects.
• DI-only awardees face a 29-month coverage desert: only ~15% have any Medicaid involvement during the combined 5-month DI + 24-month Medicare waiting period.
• For all groups with DI involvement, Medicare Part A coverage jumps to ~100% at month 25 (end of combined waiting period); public HI is essentially complete thereafter for DI-involved beneficiaries.
• SSI-only group reaches Medicaid coverage ≥90% at month 24 (90.3%) and ≥95% at month 72 among those still on SSI; represents the only subgroup without Medicare access and the only one with a sizable share (~21% at month 72) eventually in nonbeneficiary status.
• SSI-only → DI-only serial entrants experience a Medicaid coverage cliff: peak ~70% at month 5 collapses when DI benefit income disqualifies them from SSI, creating a temporary gap before Medicare begins.
• SSI exiters retain some Medicaid (36% at month 72 via Section 1619(b)), but the coverage gap between stayers (95%) and exiters (36%) widens with time.
• Affordable Care Act (ACA) Medicaid expansion (prospective at writing, 2012) would weaken SSI's role as a health insurance gateway by creating a direct Medicaid path for low-income nondisabled adults.

Concepts Introduced or Extended

• DI Medicare Waiting Period
• Disability Insurance Program

Entities Mentioned

• Kalman Rupp
• Gerald F. Riley

Quotes

"SSI plays an important role in providing a pathway to Medicaid coverage for many low-income individuals during the 29-month combined DI and Medicare waiting periods, when Medicare coverage is not available. After Medicare eligibility kicks in, public health insurance coverage is virtually complete among awardees with some DI involvement."

My Take

A rare example of exactly the right data for the question: administrative linkage of all four programs eliminates the survey under-reporting bias and allows month-to-month dynamics that surveys cannot capture. The five longitudinal eligibility patterns do most of the conceptual heavy lifting — once you understand them, the Medicaid trends follow nearly mechanically from program rules. The main contributions are empirical confirmation that rules work as designed, plus documentation of the serial-entrant coverage cliff and the SSI-exit/Medicaid-retention gap. The ACA extension note (last paragraph of conclusions) looks prescient: Medicaid expansion did reduce SSI's role as the primary health insurance gateway for working-age low-income people.