This report provides a comprehensive overview of the Medicare service, a federal health insurance program in the United States primarily for the elderly and individuals with disabilities. It details the service's function, administration, and client groups, highlighting its role in providing medical care and financial assistance. The report critically evaluates the effectiveness of the service, examining both its positive aspects, such as coverage for medications and setting medical standards, and its negative aspects, including high administrative costs and potential for fraud. Furthermore, it suggests various ways to improve the Medicare service, such as enhancing plan selection and balancing care services with costs. The report concludes with a summary of the key findings and recommendations for future development.