Health insurance stability among children with adverse childhood experiences (ACEs) is essential for accessing health care services. This cross-sectional study used an extensive, multi-year, nationally representative database of children aged 0 to 17 to examine the association between ACE scores and continuous or intermittent lack of health insurance over a 12-month period. Secondary outcomes were reported reasons for coverage gaps. Compared with children having 0 ACEs, those with 4+ ACEs had a higher likelihood of being part-year uninsured rather than year-round private insured (relative risk ratio [RRR]: 4.20; 95% CI: 3.25, 5.43), year-round public insured (RRR: 1.37; 95% CI: 1.06, 1.76), or year-round uninsured (RRR: 2.28; 95% confidence interval [CI]: 1.63, 3.21). Among children who experienced part-year or year-round uninsurance, a higher ACE score was associated with a greater likelihood of coverage gap due to difficulties with the application or renewal process. Policy changes to reduce administrative burdens may improve health insurance stability and access to health care among children who endure ACEs.