Critics who want radical changes in Medicare, the public insurance program for the elderly and disabled, often allege that the program is heading for disaster because stingy payments from the government are causing a rising number of doctors to refuse to serve Medicare patients.

In the critics’ most dire scenarios, baby boomers nearing retirement age could find that their current doctors are no longer willing to treat them under Medicare and that other doctors are turning them down as well. Those concerns have always been greatly exaggerated. Now a new analysis by experts at the Department of Health and Human Services should demolish that mythology for good.

The analysts looked at seven years of federal survey data and found that doctors are not fleeing Medicare in droves; in fact, the percentage of doctors accepting new Medicare patients actually rose to 90.7 percent in 2012 from 87.9 percent in 2005. They are not shunning Medicare patients for better-paying private patients, either; the percentage of doctors accepting new Medicare patients in recent years was slightly higher than the percentage accepting new privately insured patients.

Medicare patients had comparable or better access to medical services than the access reported by privately insured individuals ages 50 to 64, who are just below the age for Medicare eligibility. Surveys sponsored by the Medicare Payment Advisory Commission, an independent agency that advises Congress, found that 77 percent of the Medicare patients — compared with only 72 percent of privately insured patients — said they never had an unreasonably long wait for a routine doctor’s appointment last year.