Life expectancy for individuals with cystic fibrosis (CF) has increased dramatically in the last 30 yr, but it is unclear whether the improved survival has applied equally to individuals with different health insurance status. We developed a retrospective inception cohort of all 189 patients with CF born 1/1/55 to 12/31/70 who had at least one hospitalization at a university referral center. The median survival for patients with CF who were without health insurance was 6.1 yr compared with 20.5 yr for those with Medicaid and 20.5 yr for those with private insurance. Using multivariate Cox regression, health insurance and increased socioeconomic status were independently associated with longer survival. The adjusted relative risk of death was greater for the absence of health insurance than for factors previously shown to predict mortality in individuals with CF (female sex and presentation with meconium ileus). In summary, the absence of health insurance was associated with increased mortality rate in children with CF and was a stronger predictor of mortality than variables previously shown to be associated with mortality for CF. If increasing numbers of children with CF lose health insurance coverage, our results suggest that their life expectancy will decrease dramatically.