In the United States, shortages of qualified health-care professionals have created a major threat to the availability and quality of critical care services for seriously ill patients. An unprecedented, and largely unrecognized, shortage of physician intensivists in the near future will deny standard critical care services for large populations of patients with serious illnesses. If the current trend persists, shortages of these specialists, combined with the current shortages of critical care nurses, pharmacists, and respiratory therapists, will become severe by 2007 and will worsen through 2030. Numerous studies demonstrate that critical care services directed by physicians who are formally trained in critical care medicine reduce mortality in the ICU and reduce health-care costs. While people of all ages, from low-birth-weight newborns to senior citizens, benefit from treatment in the ICU, older Americans receive a disproportionate share of ICU services. The demand for ICU services, therefore, will continue to grow as the baby boom generation ages. To address the shortage, the critical care professional societies recommend that steps be taken to improve the efficiency of critical care providers, to increase the number of critical care providers, and to address the demand for critical care services.