Nonphysician clinicians (NPCs) are becoming increasingly prominent as health care providers. This study examines 10 such disciplines: nurse practitioners (NPs), physician assistants (PAs), nurse-midwives, chiropractors, acupuncturists, naturopaths, optometrists, podiatrists, nurse anesthetists, and clinical nurse specialists. The aggregate number of NPCs graduating annually in these 10 disciplines doubled between 1992 and 1997, and a further increment of 20% is projected for 2001. Assuming that enrollments remain at the levels attained in 2001, NPC supply will grow from 228000 in 1995 to 384000 in 2005, and it will continue to expand at a similar rate thereafter. The greatest growth is projected among those NPCs who provide primary care services. Moreover, the greatest concentrations of both practicing NPCs and NPC training programs are in those states that already have the greatest abundance of physicians. On a per capita basis, the projected growth in NPC supply between 1995 and 2005 will be double that of physicians. Because of the existing training pipeline, it is probable that most of the growth projected for 2005 will occur. The further expansion of both NPC and physician supply thereafter warrants careful reconsideration.