Some doctors are charging $1,500 to $1,900 a year, to give patients telephone access at all times, same-day appointments and, in some cases, house calls. Concierge practices typically limit the number of patients to no more than 600. That contrasts with as many as 3,000 in a traditional internal medicine practice.

Patients in these practices generally fall into two categories. One is busy, successful executives who want personalized care around their schedule. The other is retirees with multiple medical problems who are frustrated with the Medicare system.

For patients who can afford the service, having a doctor readily available offers peace of mind. It is comforting to know that a doctor who knows you best is just a quick phone call away.

MDVIP, an association of doctors who have this type of practice, maintains an online provider directory.