(MONEY Magazine) – Dr. Robert Marcus usually charges $75 for a routine visit to his Baltimore office. If you went to Dr. John Hartman, another internist in the city, you would pay just $25. Few prospective patients would ever have known about this disparity until Maryland's activist, consumer-oriented office of the attorney general recently published a list of fees, physician by physician, in 16 specialties. The state uncovered this information from Medicare records under the Freedom of Information Act, raising the likelihood that aggressive consumerists elsewhere will produce similar revelations. A cardiovascular stress test in Maryland's Montgomery County costs $110 to $300, for example. Podiatrists in Prince Georges County will X-ray your foot for $25 to $60. Treatment for a simple nosebleed runs $34 to $85. Obviously, there's more to choosing a doctor than the fee. But with Medicare and private insurers shifting a larger share of health-care costs onto consumers, access to price information is increasingly pertinent. Until some organization in your area gets energized, here are a few ways you can ferret out going rates. -- Make some calls. Among recommended M.D.s, phone each to determine what he charges for the care you need. Few will refuse to answer a straightforward question. Also check your state office of consumer protection and local chapters of groups like the Gray Panthers in case a survey has already been done. -- Ask your insurer. Many carriers have ''preauthorization'' programs, requiring advance approval for large expenditures like surgery or extensive tests, and while you have an expert on the phone, discuss prevailing fees. -- Try your employer. Even companies without staff medical departments have personnel-benefits counselors who routinely review medical claims and talk to insurers and thus know what the traffic will bear.