Although up to a third of the 10,000 acupuncturists in the United States are medical doctors, little is known about the acupuncture techniques they use or how their practices compare with those of nonphysician licensed acupuncturists. This is the first study providing descriptive data on physician acupuncture and comparison to nonphysician acupuncture. This study describes how a random sample of physician acupuncturists in the United States diagnose and treat chronic low back pain and contrasts their practices with those of nonphysician licensed acupuncturists. A total of 464 questionnaires were mailed to physician acupuncturists randomly sampled from 3 sources: web-based Yellow Pages, American Academy of Medical Acupuncturists (AAMA) membership, and Pain Clinics associated with American College of Graduate Medical Education-approved fellowship programs. Responses (n=137, 30%) were analyzed using descriptive statistics. The results of this survey were compared with data published from a similar survey of nonphysician licensed acupuncturists in Washington State. Physicians who perform acupuncture use a mixture of styles and emphasize neuroanatomic approaches to needle placement. Most physicians received training in French Energetic acupuncture. In contrast, most nonphysician licensed acupuncturists use a traditional Chinese medicine approach to needle placement. Despite this apparent difference in their predominant styles of acupuncture, there was a high correlation between physician and nonphysician licensed acupuncturist acupoint selection to treat low back pain. In addition to acupuncture needling, physicians use other medical treatments, whereas nonphysician licensed acupuncturists' employ a variety of traditional Chinese medicine adjuncts to needling. This study provides new information about the nature of physician acupuncture practice in the United States and how it compares to acupuncture provided by nonphysician licensed acupuncturists. Further research is necessary to determine if the different types of acupuncture provided by physicians and nonphysician acupuncturists affect treatment outcomes and costs for patients with chronic low back pain.