Primary Care Access Before and After Medicaid Expansion Under the ACA

A study published in the journal Health Affairs showed the availability of primary care appointments actually improved for people with Medicaid in the first months after the State of Michigan launched the Healthy Michigan Plan under the Affordable Care Act. The research, led by Renuka Tipirneni, M.D., M.Sc., assistant professor in the Department of Internal Medicine, reported results of a "secret shopper" study that measured the availability of primary care appointments.

What the Research Tells Us

The Affordable Care Act expands health insurance coverage to millions of Americans, but as more individuals enroll in expanded state Medicaid programs, questions remain about the availability of health care services for this influx of newly insured adults. As of June 2015, 29 states and the District of Columbia have expanded Medicaid. Medicaid and CHIP enrollment has grown by over 11.7 million since October 2013, including nearly 600,000 adults who have enrolled in Michigan’s Medicaid expansion, the Healthy Michigan Plan, since this program began in April 2014. 

This substantial coverage expansion has led some experts to express concern over access to primary care providers and long appointment wait times for the newly insured. The distinctive design of the Healthy Michigan Plan makes access to primary care providers even more essential, requiring new Medicaid beneficiaries to obtain a primary care provider appointment within 60 – 90 days of enrollment. In a 2012 survey of primary care providers in Michigan, providers expressed optimism about their capacity to accept new patients under a then-hypothetical Medicaid expansion. However, Michigan’s higher than expected enrollment in the first months of coverage expansion has prompted uncertainty about the capacity of the primary care workforce to meet this challenge. 

At the University of Michigan, Dr. Renuka Tipirneni is evaluating the implications of coverage expansion and program design on access to primary care. To provide state policymakers and other stakeholders with timely estimates of the impact of Medicaid expansion on primary care access in Michigan, Dr. Tipirneni examined primary care appointment availability and wait times for new patients with Medicaid and private insurance before and after the implementation of the Healthy Michigan Plan. 

Dr. Tipirneni and colleagues conducted a simulated patient (or “secret shopper”) study of 295 primary care practices in Michigan to measure appointment availability and wait times. Callers posed as prospective Medicaid and privately insured patients seeking to schedule new patient appointments with a primary care provider. Calls were placed during the two-week period immediately preceding the Healthy Michigan Plan start and again 3 – 4 months later. 

This study found that appointment availability for new Medicaid patients increased from 49% to 55% before and after the implementation of Medicaid expansion in Michigan, and availability for new privately insured patients decreased slightly from 88% to 86%. (Figure 1) 

Wait times for new Medicaid and new privately insured did not significantly increase before and after expansion, contrary to potential concerns that Medicaid expansion might strain the existing primary care system. Dr. Tipirneni also noted regional variation of appointment availability, suggesting that counties with higher proportions of Medicaid eligible individuals had better Medicaid appointment availability. (Figure 2) These findings are especially striking considering that this occurred during a period of rapid enrollment: approximately 350,000 adults entered the Medicaid system during the study period. 

One possible explanation of these findings is that Michigan experienced a relatively large increase in the primary care physician reimbursement rate under the ACA in 2013 – 2014, from a historically low Medicaid-to-Medicare fee ratio compared with other states. This rate bump might have prompted providers to accept additional patients, as has been suggested by previous studies. Another contributing factor may be that providers in Michigan viewed the expansion of Medicaid as an opportunity to serve a growing share of patients in Michigan with coverage by deciding to accept new Medicaid patients. In this way, the supply of primary care providers accepting Medicaid may have been responsive to the increasing Medicaid patient demand.

Impact of the Research

Dr. Tipirneni’s work is both timely and relevant. Notably, the Department of Health and Human Services recently urged states to consider this type of “secret shopper” study to directly examine acceptance of Medicaid patients in a standardized way to inform policy discussions around access to primary care. While this research provides important and early information on how the Healthy Michigan Plan is playing out, it tells only the first part of a longer narrative. More comprehensive, ongoing evaluation is necessary to fully understand the implications of this policy change. 

Examining providers’ attitudes toward accepting new Medicaid patients will help researchers and policymakers understand the impact of coverage expansion on care access and delivery, and whether or how incentives designed to increase access actually function. Further evaluation will also help the policy
community to understand how different providers and practices are accommodating the increase in acceptance of Medicaid patients. Dr. Tipirneni and other University of Michigan faculty members will address these questions, among many others, in the evaluation of the Healthy Michigan Plan via primary care practitioner interviews and a survey aimed at exploring and understanding the attitudes of primary
care providers. Findings of this future work will provide new insights regarding access to primary care under the Medicaid expansion in Michigan.

About the Researcher

Renuka Tipirneni, M.D., M.Sc., is a Clinical Lecturer in the University of Michigan Department of Internal Medicine, a recent Robert Wood Johnson Foundation Clinical Scholar, and a member of the Institute for Healthcare Policy and Innovation faculty team evaluating the Healthy Michigan Plan, Michigan’s Medicaid expansion. This work was funded by the Blue Cross Blue Shield of Michigan Foundation and the Robert Wood Johnson Foundation.


This brief's content is based on Tipirneni R, Rhodes KV, Hayward RA, Lichtenstein RL, Reamer EN and Davis MM. Primary Care Appointment Availability For New Medicaid Patients Increased After Medicaid Expansion In Michigan. Health Affairs August 2015; 34:8.