The benefits of specialist versus generalist care are a current debate in health care. This debate is particularly contentious in critical care because critical illness remains poorly defined: critical care is a relatively young specialty, there is a wide variation regarding who provides critical care, and there is doubt about the value of critical care. To help clarify these issues, in this article, we (1) define critical care; (2) define a critical care physician; (3) explore the value of critical care; (4) explore the value of a critical care physician; and (5) discuss future directions in critical care. The involvement of critical care physicians in the care of patients in the intensive care unit (ICU) appears to be associated with improved short-term outcomes, such as in-hospital mortality and ICU and hospital length of stay. The involvement of critical care physicians in the care of ICU patients appears to be associated with improved short-term outcomes. However, additional studies are needed to evaluate the population need for critical care and the effect of critical care on long-term outcomes, such as 5-year survival, functional status, and health-related quality of life.