Child enrollment in Medicaid and the Children's Health Insurance Program dropped by 828,129 children in 2018, the highest year-over-year decline in enrollment since at least 2000, according to a new study from Georgetown University's Center for Children and Families.

The decrease in enrollment likely led to an increase in the number of uninsured children in 2018, even if a "substantial share" of children moved to other forms of healthcare coverage, according to the May 30 study. The number of uninsured children rose by 276,000 in 2017 — the first increase in nearly a decade, the authors said.

Joan Alker, executive director of Georgetown University's Center on Children and Families, told reporters during a May 30 call that she is "extremely concerned" that a larger increase will occur in 2018 compared to 2017. Data on uninsured children will be issued later in 2019 through the U.S. Census Bureau's 2018 American Community Survey, Alker said.

Medicaid is the dual state and federally run health insurance program for low-income Americans. The Children's Health Insurance Program, or CHIP, is a program within Medicaid that provides health insurance to children whose families have income levels too high to qualify for Medicaid, according to the Medicaid and CHIP Payment and Access Commission, a congressional adviser on Medicaid.

CHIP covered about 9.5 million children in fiscal year 2017, according to the commission. Overall, Medicaid and CHIP covered about 39% of children in the U.S. under the age of 19 in 2017, according to the Kaiser Family Foundation, a nonpartisan healthcare policy organization.

American Academy of Pediatrics spokesperson Lanre Falusi told reporters May 30 that Medicaid and CHIP are a "lifeline" for children. The programs provide treatments like vaccinations; blood screenings; and dental, vision and mental health coverage. Falusi said crucial treatments can be delayed or skipped with even a small gap in coverage.

A concentrated decline

Nearly 70% of the enrollment decline came from seven states: California, Florida, Illinois, Missouri, Ohio, Tennessee and Texas. Each state had declines of at least 50,000 children, with California and Texas experiencing the largest population declines at 152,515 and 145,781, respectively, according to the study.

The national average percentage decline of child enrollment was about 2.2%. Tennessee and Missouri had the largest percentage decline at 10.1% and 9%, respectively, and 13 states had a higher percentage decline than the national average.

Even though overall enrollment declined, 12 states and the District of Columbia increased enrollment by 83,504 combined, according to the study. Alaska had the highest percentage increase at 3.4%, and Virginia had the highest population increase with 19,278 more enrollees in 2018 compared to 2017.

Downplaying economy's effect

While a lower unemployment rate and a growing economy can affect enrollment in government-run programs like Medicaid, the report downplayed this impact. The authors instead pointed to national changes like the repeal of the Affordable Care Act's individual mandate in 2017 and the decrease of ACA enrollment outreach funding from $100 million to $10 million in 2017. This decrease was carried over to 2018 by the Trump administration.

State-specific changes and program operations also played a part in the decrease, as did anti-immigration policies and rhetoric from the Trump administration, according to the report.

Tricia Brooks, senior fellow at the Georgetown University Center for Children and Families and lead author of the report, said unemployment trends, wage growth and coverage rates for employer-sponsored insurance would not account for the "plunge" in enrollment.

"Medicaid is sensitive to changes in the economy, but while enrollment growth historically slows during favorable economic times, it's really unusual for there to be a decline in enrollment," Brooks said. She added that the "economy has had a minimum impact, at best" and stressed that "it's far more likely that eligible children are falling through the cracks."

Edwin Park, research professor at Georgetown University's McCourt School of Public Policy and co-author of the study, said the authors examined the relationship between enrollment drops and changes in the unemployment rate at the state level, but found little connection.

Using a growing economy to explain the enrollment decrease was "overly simplistic," according to Park.