Only some 500 physicians nationwide have turned to concierge practices, according to Jack Marquis, a healthcare attorney with the Michigan law firm Warner Norcross & Judd who helped found a professional organization called the Society for Innovative Medical Practice Design. Florida Trend tallied at least 50 concierge practices in major metropolitan areas in the Sunshine State, with most in southeast Florida. Some primary care doctors also have lowered patient loads by dropping insurance plans altogether; no statistics exist on the number of these "fee-for-service" practices.

Congress's General Accounting Office reported last summer that concierge care is practiced by a very small number of physicians located mainly along the east and west coastlines. The American Medical Association reported the trend is "self-limiting" because the more physicians charge for services, the smaller patient demand is for those services. But that is not the experience of a fast-growing Boca Raton company called MDVIP, which helps physicians convert to and manage concierge practices.

In November, Inc. magazine ranked MDVIP one of the fastest-growing companies in the country, with three-year sales growth of 1,841%. In March, the company, which was founded in late 2000, had expanded to 21 markets in 15 states. The company now has contracts with more than 100 physicians covering more than 33,000 patients nationwide. Its average patient renewal rate is 95%. The 33,000 patients pay their doctors an average fee of $1,500, $500 of which goes to MDVIP, translating into annual revenue of $16.5 million.

Dr. Edward Goldman, CEO and co-founder of MDVIP, who had a family practice in south Florida for 25 years, says he believes the company could widen rather than restrict access to primary care. The number of primary physicians in the U.S. already is in precipitous decline, due to issues like job dissatisfaction and lower pay relative to other medical specialties.

Only about 33% of med school students now go into primary care, down from about 50% historically. Meanwhile, more than half of all family doctors in the U.S. report plans to retire or otherwise give up practices in the near future. "We don't believe our numbers will be enough to effect access to primary care," says Goldman. "But other trends in medicine are impacting access, and we believe our model will actually attract new doctors into the field."