There are several reasons that boomers—the 78 million Americans born between 1946 and 1964—could have difficulty finding a doctor if they retire to small towns over the next 20 years. First, many primary-care doctors prefer to live and work in urban areas because of greater cultural opportunities, better schools and more job opportunities for spouses. Also, Medicare pays rural doctors less per procedure than urban physicians because their operating costs are supposedly less. That makes rural doctors less likely to accept Medicare patients. Because of cuts to Medicare reimbursement for doctors planned under the federal healthcare overhaul, the shortage is likely to get worse, said Mark Pauly, professor of healthcare management at the University of Pennsylvania.