Lower socioeconomic status (SES) has consistently been associated with poorer outcomes in individuals with cystic fibrosis (CF). Previous studies have compared outcomes for children with and without private insurance coverage, however the potential role of changes in insurance status on early health outcomes in children with CF remains unknown.

To describe the variability in insurance status in early childhood and to evaluate whether insurance variability was associated with poorer outcomes at age 6.

Retrospective observational study using the Cystic Fibrosis Foundation Patient Registry. Insurance status was defined as: always private (including Tricare), exclusively public, or intermittent private insurance (private insurance and exclusively public insurance in separate years) during the first 6 years of life. Outcomes at age 6 included body mass index (BMI) and FEV1 percent predicted (maxFEV1pp).

From a 2000–2011 birth cohort (n = 8,109), 42.3% always had private insurance, 30.0% had exclusively public insurance, and 27.6% had intermittent private insurance. BMI percentiles did not differ between groups; however, children with intermittent private insurance and exclusively public insurance had a 3.3% and 6.6% lower maxFEV1pp at age 6, respectively, compared to those with always private insurance.

A substantial proportion of young children in a modern CF cohort have public or intermittent private insurance coverage. While public insurance has been associated with poorer health outcomes in CF, variability in health insurance coverage may also be associated with an intermediate risk of disparities in lung function as early as age 6.