In the U.S. for-profit, insurance-driven healthcare system a conundrum arises, which presents a complex challenge, with health plans enroll beneficiaries who are covered by both Medicare and Medicaid. These people are known as dually eligible beneficiaries. The proportion of people who are Medicare beneficiaries and who are also enrolled in Medicaid varies at any given time, but it runs into several million people. Medicare is a national health insurance program, administered by the Centers for Medicaid and Medicare Services of the U.S. federal government. It provides health insurance for Americans aged 65 and older who have worked and paid into the system through the payroll tax.