1. Improper payments: improvements needed in CMS and IRS controls over health insurance premium tax credit : report to Congressional committees Publication: Washington, D.C. : U.S. Government Accountability Office, July 2017 Subject(s): Cost Sharing -- economicsGovernment RegulationHealth Insurance Exchanges -- economicsIncome TaxEligibility DeterminationInsurance, Health -- economicsHumansUnited StatesUnited States. Internal Revenue Service.United States.Centers for Medicare & Medicaid Services (U.S.)