Many doctors listed as accepting Medicaid managed care plans are not in fact available to treat beneficiaries — which include many people with disabilities — federal investigators have found. (Darin Oswald/Idaho Statesman/TNS)

A significant number of doctors purportedly accepting Medicaid are not actually offering treatment to the program’s beneficiaries, a new investigation finds.

More than half of primary care providers and specialists polled were not able to offer appointments to patients on Medicaid, according to a report released Tuesday from the U.S. Department of Health and Human Services’ Office of Inspector General.

The reasons that physicians were unavailable to Medicaid beneficiaries — which include many people with disabilities — varied, but in 35 percent of cases investigators found that doctors were not at the locations listed by the program’s provider directory.

“Callers were sometimes told that the practice had never heard of the provider or that the provider had practiced at the location in the past but had retired or left the practice. Some providers had left months or even years before the time of the call,” Inspector General Daniel R. Levinson wrote in his report.

Meanwhile, 8 percent of providers indicated that they were not participating in the plan and a similar number of physicians said they were not accepting new patients.

For the report, federal investigators called a random sampling of 1,800 primary care providers and specialists that were listed as participating in Medicaid managed care plans in 32 states.

In cases where patients could schedule an appointment, investigators found that the median wait time was two weeks, though a substantial number of doctors were not available for at least one or two months.

Primary care providers were less likely to be available than specialists, though wait times tended to be longer for specialty providers, the report found.

“When providers listed as participating in a plan cannot offer appointments, it creates a significant obstacle for an enrollee seeking care. Moreover, it suggests that the actual size of provider networks may be considerably smaller than what is presented by Medicaid managed care plans,” Levinson said in his findings.

In a response to the report, Marilyn Tavenner, administrator of the Centers for Medicare and Medicaid Services said her agency will work with states to “assess network adequacy and improve the accuracy of managed care organizations’ information.”