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Prevalence and Predictors of Underinsurance Among Low-Income Adults



Millions of adults will gain Medicaid or private insurance in 2014 under the Affordable Care Act, and prior research shows that underinsurance is common among middle-income adults. Less is known about underinsurance among low-income adults, particularly those with public insurance.


To compare rates of underinsurance among low-income adults with private versus public insurance, and to identify predictors of being underinsured.


Descriptive and multivariate analysis of data from the 2005–2008 Medical Expenditure Panel Survey.


Adults 19–64 years of age with family income less than 125 % of the Federal Poverty Level (FPL) and full-year continuous coverage in one of four mutually exclusive insurance categories (N = 5,739): private insurance, Medicaid, Medicare, and combined Medicaid/Medicare coverage.


Prevalence of underinsurance among low-income adults, defined as out-of-pocket expenditures greater than 5 % of household income, delays/failure to obtain necessary medical care due to cost, or delays/failure to obtain necessary prescription medications due to cost.


Criteria for underinsurance were met by 34.5 % of low-income adults. Unadjusted rates of underinsurance were 37.7 % in private coverage, 26.0 % in Medicaid, 65.1 % in Medicare, and 45.1 % among Medicaid/Medicare dual enrollees. Among underinsured adults, household income averaged $6,181 and out-of-pocket spending averaged $1,115. Due to cost, 8.1 % and 12.8 % deferred or delayed obtaining medical care or prescription medications, respectively. Predictors of underinsurance included being White, unemployed, and in poor health. After multivariate adjustment, Medicaid recipients were significantly less likely to be underinsured than privately insured adults (OR 0.22, 95 % CI 0.17–0.28).


Greater than one-third of low-income adults nationally were underinsured. Medicaid recipients were less likely to be underinsured than privately insured adults, indicating potential benefits of expanded Medicaid under health care reform. Nonetheless, more than one-quarter of Medicaid recipients were underinsured, highlighting the importance of addressing cost-related barriers to care even among those with public coverage.

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Dr. Magge was supported by the National Research Service Award grant 6 T32 HP10263 from the National Institutes of Health. Dr. Magge had full access to all of the data in the study and takes responsibility for the integrity of the data and the accuracy of the data analysis. All authors have no conflicts of interest to disclose. Dr. Sommers is currently serving as a Senior Advisor in the U.S. Department of Health & Human Services, but this work was conducted while he was a faculty member at the Harvard School of Public Health, and in no way represents the views of the Department. We thank Tracey Wilkinson, M.D., Caroline Kistin, M.D., Webb Long, M.D., and Neil Gupta, M.D for their thoughtful manuscript review.

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All authors have no conflicts of interest to declare.

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Correspondence to Hema Magge MD, MS.



Table 5 Insurance Characteristics Excluding Those Reporting Income Equal to Zero* (n = 5,227)

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Magge, H., Cabral, H.J., Kazis, L.E. et al. Prevalence and Predictors of Underinsurance Among Low-Income Adults. J GEN INTERN MED 28, 1136–1142 (2013).

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  • underinsurance
  • health reform
  • Medicaid
  • low-income