Research Brief: Provider acceptance of Medicaid grew slightly after ACA expansion

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Beginning in 2014, a provision in the Affordable Care Act (ACA) greatly expanded who was eligible for Medicaid insurance coverage. As a result, 15 million new people signed up for the federal program, making Medicaid the health care insurer for roughly one in seven adults.

A new study from the University of Minnesota School of Public Health, recently published in the journal Health Affairs, shows physician acceptance of Medicaid only increased slightly after ACA expansion and a majority of the Medicaid patients are being seen by providers who already accept the insurance.

“It's mostly a ‘good news’ story because there were concerns that people wouldn't be able to get care at all,” said lead author and Assistant Professor Hannah Neprash. “There is more care for these patients, however, it's not equally distributed across providers.”

Historically, some providers have refused to see Medicaid patients due to the program’s complex administrative steps for payment, its low reimbursement rates and other factors.

To find if the large expansion of Medicaid made treating its patients more appealing to providers, Neprash analyzed the patient and bill data of nearly 4,000 physicians between 2013 and 2015.

The study found that:

  • Before the expansion, nine out of 10 primary care physicians treated at least some Medicaid patients, but Medicaid represented a small share (less than 10 percent) of the average physician’s overall patient panel.
  • Overall, primary care physicians increased their participation in Medicaid by 1.6 percentage points, raising their numbers of Medicaid patients on average from 7.8 percent in 2013 to 9.4 percent in 2015. This increase was driven entirely by physicians in expansion states treating more Medicaid patients.
  • In 2015, nearly two-thirds of physicians overall maintained their 2013 level of Medicaid participation. Of those who changed categories of Medicaid participation, more transitioned to a higher rather than a lower proportion of adult Medicaid patients.

The results show that physicians treated more Medicaid patients after the 2014 expansion, but those patients are a very small share of the total patients they treat and Medicaid patients are still concentrated among a small number of providers.

Neprash hopes the study’s results will ease critics’ concerns that physicians would see fewer Medicaid patients or cease participating in the program altogether. She added that policy-makers may want to consider increasing reimbursement or reducing the administrative hurdles to reimbursement in any future efforts aimed at encouraging physicians to treat more Medicaid patients.  

Neprash is continuing her analysis of Medicaid’s expansion by looking at factors such as how the addition of new patients is affecting appointment wait times and length, and provider and patient experience.

A grant from the Robert Woods Johnson Foundation funded the study.


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