Highlight on Michigan: Medicaid expansion did not cause crowding

The expansion of Michigan’s Medicaid program—the Healthy Michigan Plan—did not impede access to care, according to a University of Michigan Health System study. Despite concerns that new rules and growth would be detrimental to those signed up for both the Healthy Michigan Plan and private insurance, according to the study, there was no significant increase in wait times for either group. In addition to not hindering access, expansion improved access for some individuals. For Healthy Michigan enrollees, the odds of getting an appointment increased in the first year of expansion.

Earlier research

The study, published in the American Journal of Managed Care (AJMC), is an extension of an earlier study that examined primary care appointment availability and wait times for new patients with Medicaid and private insurance before and 4 months after Michigan’s Medicaid expansion on April 1, 2014. In those first four months, the researchers found an initial increase in primary care appointment availability for new Medicaid patients and no lengthening of wait times.


The subsequent study—like the earlier research—used a simulated patient or “secret shopper” method. Trained research staff called a random sample of primary care practices, before and after Medicaid expansion, to request a new patient appointment. Wait times were calculated as the difference between the date of the call and the appointment date. The study evaluated 295 clinics.

Appointment availability

The percentage of clinics accepting new Medicaid patients increased from 49 percent, before expansion, to 55 percent 12 months after expansion. The availability of appointments for privately insured individuals fell from 88 percent of clinics before expansion to 86 percent after expansion. The number of Medicaid appointments scheduled with non-physician providers increased from 8 percent before expansion to 21 percent 12 months after expansion. For individuals with private insurance, the proportion of appointments scheduled with non-physician providers increased from 11 percent before expansion to 19 percent 12 months after expansion.

Wait times

For clinics accepting Medicaid patients, median wait times remained stable over the first year of Michigan’s Medicaid expansion. For those with private insurance, median wait times increased from 7 to 10 days in the first year after expansion. Additionally, median new patient wait times were within two weeks. According to the study, 95 percent of new patient wait times satisfied the Health Michigan Law’s requirement that Health Michigan beneficiaries have access to an initial day primary care appointment within 90 days of enrollment.


Medicaid expansion in Michigan had a largely positive impact on patient access to care. With the exception of small increases in wait times for some privately insured individuals, the Health Michigan Program served to improve, rather than hinder, the likelihood and timeliness of care. The researchers concluded that increases in appointment availability for new Medicaid patients was likely attributable to increases in the number of non-physician appointments. As such, the study recommended that future research should examines other team-based approaches—like the use of non-physician appointments—to further improve primary care access.