Barbara Starfield and colleagues present evidence that having more primary care physicians and fewer specialists per capita is associated with lower mortality rates. These analyses stand in contrast to those guiding national workforce policy recommendations, which use current physician-to-population ratios as a normative reference for future physician requirements. Proponents of physician training expansion need to establish a body of evidence that having additional physicians will lead to improved health and well-being of patients and populations. Research to date, in contrast, indicates that physician workforce levels, particularly of specialists, are not a primary factor in determining health outcomes.