Most physicians engage in a specialty practice, with almost all new licensees being specialists. Specialties range from narrow interests in an obscure disease to family practice. The more narrow the specialty is, the smaller is the potential patient population. If patients selected physicians at random, then narrow interest specialists would spend all their time turning away patients. The reality is that specialists with narrow interests traditionally depend upon referrals from other physicians rather than marketing their services to patients directly.

The most important limitation on a physician’s willingness to accept a patient is that of a self-imposed specialty. Although there is nothing in the law to prevent a dermatologist from practicing general medicine, most dermatologists will decline to regulate a patient’s diabetes. In the same sense, a family physician may be willing to treat acne and diabetes but unwilling to perform surgery. These limitations cause a problem only if they are not known to the patient when making an appointment. For example, a patient with severe hypertension makes an appointment with an internist. After taking the patient’s medical history, the physician tells the patient that he limits his practice to gastroenterology. The patient would be justified in refusing to pay for the visit. More important, this unnecessary appointment may delay proper treatment for the patient’s condition. In this situation, the physician should arrange for a referral and send the patient to an emergency room if he is concerned with the delay in seeing the second physician.