To the Editor The Viewpoint by Ms Gudbranson and colleagues calculating the number of physicians needed in the United States did not consider the numerous roles that physicians play in the health care sector. If administrative workload, teaching of trainees (medical students, residents, and fellows), and research are included, the estimates may be quite different. The administrative burden of billing, coding, and entering data in electronic medical records requires several extra hours of work per week. No physician can be expected to assign 100% of their time to clinical care, and although some previously published models account for clinical full-time equivalents, it is unclear whether Gudbranson and colleagues took this into consideration. Furthermore, models accounting for clinical full-time equivalents project a serious shortage of physicians over the next decade. A report prepared for the Association of American Medical Colleges notes that the demand for physicians in 2025 will exceed supply by 46 100 to 90 400. Physicians in the United States (excluding residents) work an average of 49.6 hours per week compared with 44.9 hours for lawyers, 43.0 hours for engineers, and 37.3 hours for registered nurses. This estimate does not take into account being on call when physicians need to be immediately available but not present on-site.