Insurance gaps at age-19 and age-26 health insurance eligibility thresholds by childhood-onset condition severity, Colorado 2014-2018

Objective: To characterize health insurance gap patterns related to age-19 Medicaid and age-26 commercial age-eligibility cutoffs.

Study setting and design: This descriptive analysis spans 2014-2018, after Affordable Care Act implementation, but before COVID-19 emergency provisions. We defined insurance gaps as ≥3 consecutive months without observed enrollment, preceded and followed by ≥1 month of enrollment and stratified results by insurance source and clinical severity (e.g., with chronic, complex, or disabling conditions or not).

Data sources and analytic sample: The Colorado all-payer claims database provided data for enrollees aged 10-29, 52% (649,346) of whom were initially Medicaid insured, whereas 47% (576,596) were commercially insured.

Principal findings: The percent of enrollees with insurance gaps peaks within six months of turning age-19 and age-26-at 8.9% Medicaid and 8.7% commercial, respectively. The percentage point difference between ages 27-28 and 11-18 was 3.3 percentage points higher for prior Medicaid recipients (p < 0.001) and 2.2 percentage points greater for prior commercial enrollees (p < 0.001). Relative to the other clinical severity groups, young adults with disabling health conditions who were initially Medicaid insured had the lowest peak gap rate, 5.7%, compared with 10.5% among the previously commercially insured; this latter finding was sensitive to gap specification.

Conclusions: Young adults would likely benefit from greater attention to age-19 and age-26 health insurance "unwinding."