BACKGROUND AND PURPOSE: Medication access is crucial to secondary stroke prevention. We assessed medication access and associated barriers to care across region and time in a national sample of US stroke survivors. METHODS: Among all 5840 black or white stroke survivors aged > or =45 years responding to the National Health Interview Survey years 1997 to 2004, we examined inability to afford medications within the last 12 months across region (Northeast, Midwest, West, South) and time. With logistic regression, we adjusted associations between medication inaffordability and region and time for age, sex, race, neurological disability, comorbidity, health status, insurance, income and out-of-pocket medical expenses. RESULTS: In 2004, approximately 76,000 US stroke survivors were unable to afford medications. Lower medication affordability was reported among stroke survivors who were <65 years old, black, female, had high comorbidity or low health status. Compared with stroke survivors able to afford medications, those unable more frequently reported lack of transportation (15% versus 3%; P<0.001), no health insurance (16% versus 3%; P<0.001), no usual place of care (6% versus 2%; P=0.001), income <$20,000 (66% versus 40%; P<0.001) and out-of-pocket medical expenses > or =$2000 (35% versus 25%; P<0.001). From 1997 to 2004, inability to afford medications increased significantly from 8.1% to 12.7% (P(trend)=0.01) overall and increased in all US regions except the Northeast. CONCLUSIONS: We identified a vulnerable stroke survivor population with reduced medication access and increased barriers to medical care. Membership in this population has grown substantially from 1997 to 2004, potentially leading to increased recurrent stroke incidence.