A half-decade ago, my primary care doctor left the practice where he had worked for several years and opened his own concierge medicine business. A quick note: I know differences exist between concierge medicine and direct primary care, but for this column, I'm interchangably using those terms. His own panel sits around 700 patients—a deliberate departure from the 200-400 patients concierge medicine popularized in the model's early days. Concierge medicine also doesn’t allow for shift-type medicine. “Out of 200-300 concierge patients,” Mullen said, “they are all the 5%.”