Key PointsQuestionDoes the use of targeted therapies for non–small cell lung cancer (NSCLC) vary across state Medicaid programs?FindingsThis cross-sectional study found substantial variation in the use of targeted therapies forEGFR- andALK-altered NSCLC across Medicaid programs, with evidence of underuse in 30 of 33 states. The observed variation was associated with Medicaid policies, oncologist density, and state gross domestic product per capita.MeaningThis study suggests that targeted therapies are underused in many state Medicaid programs, limiting access to efficacious treatments; attention is needed for state policies and characteristics that may limit access to these useful drugs.