A larger percentage of U.S. children between 2015 and 2019 relied on Medicaid, the Children’s Health Insurance Plan (CHIP), or Affordable Care Act (ACA) Marketplace plans for continuous health insurance coverage than were continuously covered by an employer-sponsored health plan, according to a recent analysis. About 26.0% of children between 2015 and 2019 were continuously in an employer-sponsored health plan. About 13.8% were continuously enrolled in a publicly subsidized option (Medicaid, CHIP, or ACA Marketplace plans). Another 17.9% switched between publicly subsidized options and employment-based or other insurance options, but were continuously covered. In total, 57.7% of children were never uninsured during childhood. The remaining 42.3% had a period of uninsurance.
Over the course of childhood, children’s source of health insurance coverage changed an average of 2.5 times, and a median of 1.8 times across five insured status options: Medicaid, CHIP, ACA Marketplace plans, employer-sponsored, or uninsured. By age 18, about 78.5% of children were at one point during childhood enrolled in employment-based private insurance, and 60.9% had ever enrolled in Medicaid or CHIP.
Across all states, among children with Medicaid or CHIP coverage at birth, 35.1% remained continuously covered in Medicaid or CHIP or Marketplace plans, and 44.8% became uninsured at some point. The percentage of children with Medicaid or CHIP at birth who were ever uninsured was higher in Medicaid non-expansion states, at 58.6%, compared to those in expansion states, at 36.2%. Upcoming policy changes that reduce Medicaid funding and enrollment could worsen the risk of coverage gaps for children, the researchers concluded.
The analysis focused on the insurance history of U.S. children from birth to their 18th birthday from 2015 through 2019, after implementation of major ACA provisions in 2014 and before the start of the COVID-19 public health emergency in 2020. Data for the analysis was from multiple federal and state sources to include income and program participation, birth records, health coverage enrollment, and state Medicaid and CHIP policy information. The researchers used the data to simulate a nationally representative starting population of 100,000 children. Using this simulation population, the researchers estimated the effects on policy changes affecting Medicaid and CHIP and ACA Marketplace enrollment.
These findings were presented in Insurance Dynamics During Childhood in the Fragmented U.S. Health System, by Ye Shen, MSPH; Benjamin D. Sommers, M.D., Ph.D.; Laura A. Hatfield, Ph.D.; and colleagues. The goal was to estimate insurance dynamics in relation to Medicaid or CHIP and uninsurance during childhood under post-ACA policy conditions prior to COVID-19, according to the study.
The full text of Insurance Dynamics During Childhood in the Fragmented U.S. Health System was published on September 24, 2025, by JAMA. A free abstract is available (accessed October 15, 2025).
For more information, contact: Ye Shen, MSPH, Ph.D. Candidate in Health Policy, Harvard University, 8 Story Street, Suite 380, Cambridge, Massachusetts 02138; Email: ye_shen@fas.harvard.edu; Website: https://healthpolicy.fas.harvard.edu/people/ye-shen
January 2026 00US26EUA0003