Medical Physicists in the USA, as in other parts of the world, practice in the subfields of: therapeutic radiological physics, diagnostic radiological physics, medical nuclear physics and medical health physics, performing clinical service and consultation, research and development, and teaching. They are organized under the umbrella of the American Association of Physicists in Medicine (AAPM), which is a scientific, educational, and professional organization of more than 7,000 medical physicists. The other organizations, which influence the medical physics profession, are the American College of Medical Physics, the American Board of Medical Physics, the American Board of Radiology (ABR) and more recently the Commission on Accreditation of Medical Physics Educational Programs (CAMPEP). In response to the new policies of the ABR requiring additional residency, similar to the training of medical doctors, the medical physics community is looking into alternative training pathways such as residency and a new professional Doctorate in Medical Physics (DMP) degree, in addition to the traditional graduate level degrees. The recent changes in the health insurance laws along with the recent publicity on computed tomography (CT) perfusion dose and tragic errors in radiotherapy treatments, which resulted in some US Congressional hearings to improve patient safety in the medical use of radiation, will have legislative effects on the medical physics profession, as well.