Percentage of U.S. Americans covered by Medicaid 1990-2023

The percentage of Americans covered by the Medicaid public health insurance plan increased from 17.8 percent in 2020 to around 18.9 percent in 2023. However, the percentage of those insured through Medicaid remains lower than the peak of 19.6 percent in 2015. 

The expansion of Medicaid

The Affordable Care Act (ACA) provided the option for states to expand Medicaid eligibility to people whose income was below a particular threshold. The ACA’s major coverage expansion came into force in 2014, and the number of individuals estimated to be enrolled in Medicaid has since surpassed 75 million. More than 28 million children were enrolled in the program in 2018, representing 38 percent of overall Medicaid enrollment.

State Medicaid coverage

Initially, the ACA mandated that all state Medicaid programs would have to be extended to provide medical coverage to nearly all low-income groups. However, the Supreme Court rejected that part of the act in 2012, leaving the door open for states to make their own decision on whether they expand their plans. As of September 2021, 39 states plus the District of Columbia have adopted the Medicaid expansion.