The success of Medicare depends on accurately assessing the impact of constant advances in science and technology on patient care. There is simply no substitute for physicians' clinical expertise when gauging how much work and resources go into one medical service compared with another. No one knows more about what is involved in providing services to Medicare patients than the physicians who care for them. An AMA-convened committee of independent physicians has taken the initiative to evaluate medical services and recommend adjustments to Medicare that have decreased payments, freeing more than $2.5 billion to be redistributed to other services.