Public-private substitution among Medicaid adults: evidence from Ohio.

Unlabelled: OBJECTIVE To estimate substitution from private insurance to public coverage among adult Medicaid enrollees.

Data sources: 2004 and 2008 Ohio Family Health Surveys (OFHS) STUDY DESIGN: Substitution is estimated from respondents' self-reported current insurance coverage and coverage prior to Medicaid enrollment. A linear probability model estimates the association between prior private coverage and respondent characteristics.

Data collection/extraction methods: Random digit dialing telephone survey of 50,944 Ohio residents in 2008-2009 and 39,953 in 2003-2004.

Principal findings: Few adult Medicaid enrollees in Ohio voluntarily replace their private coverage with Medicaid. In 2008, only 2.9% of new Medicaid adults voluntarily substituted public for private coverage (4.6% in 2004). Of these 2.9% who voluntarily substituted from private to public coverage, 38% reported that they could not afford their employer sponsored plan. The multivariate results for all private to Medicaid transitions find few significant differences, other than income, in the probability of transition.

Conclusions: Few transitions from private coverage to Medicaid are voluntary, and substitution is a minor issue among current Ohio Medicaid adults.