Health insurance coverage is critical for ensuring access to recommended health care in the United States. This study investigated the associations of health insurance coverage disruptions, also known as coverage churn, and receipt of breast and colorectal cancer screening. Adults who were age-eligible and younger than 65 years (range, 50-64 years) for breast (n=17,128 women) and colorectal (n=32,562 individuals) cancer screening were identified from 5 years of the National Health Interview Survey. Adults were categorized into five groups based on insurance type at survey (private, public, none) and prior coverage disruptions within the past year. Screening outcomes included: (1) ever-screened, (2) past-year screening, and (3) guideline-concordant screening. Separate multivariate logistic regression models were used to evaluate the associations between insurance coverage disruptions and cancer screening. Among adults who had coverage at the time of the survey, 3.1% with private insurance and 6.5% with public insurance reported prior coverage disruptions. Individuals without health insurance coverage had the lowest level of screening. Among individuals who had private coverage, prior disruptions were associated with lower guideline-concordant screening in adjusted analyses (breast cancer screening: adjusted prevalence ratio [aPR], 0.82; 95% confidence interval [CI], 0.75-0.89; colorectal cancer screening: aPR, 0.78; 95% CI, 0.72-0.86); among those who had public coverage, prior disruptions were also associated with lower guideline-concordant breast cancer screening (aPR, 0.73; 95% CI, 0.60-0.89) and colorectal cancer screening (aPR, 0.84; 95% CI, 0.72-0.99). Health insurance coverage disruptions were associated with lower past-year and guideline-concordant breast and colorectal cancer screening. The current findings underscore the importance of stable health insurance coverage to improve cancer screening and early detection when treatment is most effective.