CHICAGO — Patients without health insurance were a slimmer percentage of physicians’ total patient mix by health insurance status in 2016 compared to 2012, according to new research from the American Medical Association (AMA). While the change was expected given historic gains in health insurance coverage, AMA research shows the shrinking percentage of uninsured patients in physician practices was driven by states that expanded Medicaid programs under the Affordable Care Act (ACA).

“The overall picture from new physician-reported data is of more patients covered and fewer uninsured, but the findings also indicate that the improvement along those lines was concentrated in states that expanded their Medicaid programs under the ACA,” said David O. Barbe, M.D. “Expanding Medicaid has provided much needed coverage to our low-income patients, improved access to care, and enhanced the health and well-being of the newly insured. Medicaid expansion is not simply a budget issue. Lawmakers must also consider the real human effects of this decision, including the health and well-being of those who have gained coverage under expansion.”

The AMA research shows 75.6 percent of physicians had practices that included uninsured patients in 2016, compared to 81.3 percent in 2012. The average share of uninsured patients in a physician practice was 6.1 percent of the total patient mix in 2016, compared with 6.9 percent in 2012.

The AMA data shows that while uninsured patients accounted for a smaller share of the overall patient mix in physician practices, the share of Medicaid patients increased. These changes by 2016 were largely driven by physicians in the 31 states and the District of Columbia that had expanded Medicaid programs under the ACA.

Among physicians in expansion states, the average Medicaid patient share increased from 16.2 percent in 2012 to 17.6 percent in 2016. During the same period, the average uninsured patient share decreased from 6.4 to 5.4 percent. In contrast, among physicians in non-expansion states, there was essentially no change in Medicaid patient load from 2012 to 2016, and only a modest decline in uninsured involvement that was not statistically significant.

“The most striking difference,” the report notes about expansion versus non-expansion states, “was in the percentage of physicians with uninsured patients. While this fell by more than 7 percentage points in expansion states, the drop in non-expansion states was only 2.2 percentage points.”

In addition to tracking the share of uninsured in physicians’ patient mix, the AMA research provides the most up-to-date breakdown of coverage type. The research found that in 2016 private insurance covered 43.4 percent of physicians’ patients, while Medicare covered 29.3 percent, Medicaid covered 16.9 percent, and workers compensation or other payer covered 4.3 percent. In 2012, private insurance covered 42 percent of physicians’ patients, while Medicare covered 30.1 percent, Medicaid covered 15.9 percent, and workers compensation or other payer covered 5.1 percent.

The new study is the latest addition to the AMA's Policy Research Perspective series that examines long term changes in practice arrangements and payment methodologies. For additional information from the new study, including an examination of the 2016 patient mix by specialty and practice type, go to the AMA website to download a copy.