‘Ghost’ physicians in Medicaid: Nearly 1 in 3 enrollees see no Medicaid patients

Almost 30% of physicians listed as participating in Medicaid did not actually see a single Medicaid patient in 2021, according to a new national study that raises fresh questions about access for the program’s nearly 80 million enrollees.

The research, led by Jane Zhu, M.D., an associate professor of medicine in general internal medicine and geriatrics at Oregon Health & Science University (OHSU), linked Medicaid enrollment files with administrative claims from 2019 through 2021. The team focused on five specialties that play key roles in outpatient care: primary care, psychiatry, cardiology, dermatology and ophthalmology.

Across those specialties, between 68% and 89% of physicians were enrolled in Medicaid. But enrollment did not always translate into care.

Nearly 28% of Medicaid-enrolled physicians delivered no care at all to Medicaid beneficiaries in 2021, the authors reported in Health Affairs.

The study refers to these clinicians as "ghost" physicians.

“Low physician participation in Medicaid is a commonly cited reason for access gaps and unmet need in Medicaid,” Zhu said in an Oregon Health & Science University news release. “If patients aren’t able to access the care they need, they may delay or forego care altogether, which is not only bad for patient outcomes, but also bad for the health system overall.”

Participation varied widely by specialty. More than 40% of psychiatrists counted as Medicaid-enrolled did not see any Medicaid patients in a given year, making psychiatry the specialty with the highest share of ghost physicians. Primary care physicians, by contrast, were the most likely to be high-volume "core" participants who provided care for large panels of Medicaid patients.

The study also identified a group of clinicians at the other end of the spectrum: high-volume Medicaid physicians.

Roughly one-third of enrolled physicians saw more than 150 Medicaid patients a year, suggesting that a relatively small subset of clinicians is providing the bulk of Medicaid care.

That uneven distribution of participation can translate into long wait times and dead ends for patients who rely on plan directories to find a doctor, Zhu noted.

“Patients may call providers who say they are enrolled in Medicaid, but those calls go nowhere,” she said. “People give up because those providers aren’t actually available to see them.”

Although many physicians kept a consistent pattern of participation over the three-year study period, the researchers did see some movement. About one-fifth of ghost physicians and one-third of “peripheral” physicians — defined in the paper as those who saw one to 10 Medicaid enrollees a year — shifted into higher-engagement categories between 2020 and 2021.

The analysis drew on the Transformed Medicaid Statistical Information System Analytic Files, a national data set that captures enrollment and claims for state Medicaid programs. The authors said the results mirror earlier research in Oregon’s Medicaid program that found similarly high levels of ghost providers, pointing to a broader national pattern.

Zhu said the findings underscore the limits of relying on enrollment files to assess network adequacy and patient access.

“Maintaining access to care is a really big problem with increasing demand for services and workforce shortages,” she said. “A clearer picture would help policymakers better spend public dollars on levers that meaningfully impact provider participation.”

Co-authors on the study included Kirbee Johnston, M.P.H., Kyle Hart, M.S., and John McConnell, Ph.D., of the OHSU Center for Health Systems Effectiveness, along with Daniel Polsky of Johns Hopkins University.

For primary care and specialty practices that regularly see Medicaid patients, the study suggests that a relatively small group of clinicians is carrying much of the load.

For Medicaid enrollees and the clinics that care for them, the authors argue, a more accurate picture of real-world participation will be essential to addressing network gaps and planning workforce and payment reforms.