1. The effect of Medicaid expansion on marketplace premiums Author(s): Sen, Aditi P., authorDeLeire, Thomas C., author Publication: [Washington, D.C.] : Department of Health and Human Services, Office of the Assistant Secretary for Planning and Evaluation, September 6, 2016 Subject(s): Health Insurance Exchanges -- economicsMedicaid -- utilizationMedicaid -- economicsHealth Care CostsUnited StatesUnited States.