BACKGROUND: Disabled Americans who qualify for Medicare coverage typically have multiple chronic conditions, are highly dependent on effective drug therapy, and have limited financial resources, putting them at risk for cost-related medication nonadherence (CRN). Since 2006, the Part D benefit has helped Medicare beneficiaries afford medications.

OBJECTIVE: To investigate recent national trends in medication affordability among this vulnerable population, stratified by morbidity burden.

DESIGN AND SUBJECTS: We estimated annual rates of medication affordability among nonelderly disabled participants in a nationally representative survey (2006-2011, n=14,091 person-years) using multivariate logistic regression analyses.

MEASURE: Survey-reported CRN and spending less on other basic needs to afford medicines.

RESULTS: In the 6 years following Part D implementation, the proportion of disabled Medicare beneficiaries reporting CRN ranged from 31.6% to 35.6%, while the reported prevalence of spending less on other basic needs to afford medicines ranged from 17.7% to 21.8%. Across study years, those with multiple chronic conditions had consistently worse affordability problems. In 2011, the prevalence of CRN was 37.3% among disabled beneficiaries with > /= 3 morbidities as compared with 28.1% among those with fewer morbidities; for spending less on basic needs, the prevalence was 25.4% versus 15.7%, respectively. There were no statistically detectable changes in either measure when comparing 2011 with 2007.

CONCLUSIONS: Disabled Medicare beneficiaries continue to struggle to afford prescription medications. There is an urgent need for focused policy attention on this vulnerable population, which has inadequate financial access to drug treatments, despite having drug coverage under Medicare Part D.