Objective: To (1) estimate the lifetime prevalence of suspected and diagnosed traumatic brain injury (TBI) based on parent report overall and select sociodemographic characteristics; and (2) describe differences in prevalence of health conditions and health-related risk factors by whether a child had a lifetime history of diagnosed TBI. Study design: We analyzed data from the 2020 National Survey of Children's Health, a cross-sectional address-based survey of US households. A categorical variable was created on the basis of parent responses to 3 questions inquiring about their suspicion of their child having a brain injury, if they sought medical care, and if the health care provider provided a diagnosis. Parents also were asked to report on their child's additional health conditions, functional indicators, school and social factors, and health care access and service use. Results: The prevalence of lifetime diagnosed TBI was 4.2% (95% CI 3.8-4.5). Children with a parent-reported lifetime history of diagnosed TBI were more likely to have a variety of health conditions, special health care needs, disabilities, activity limitations, missed days of school, and unmet care coordination needs, compared with those without a history. However, they were more likely to have a usual source of sick care and to receive more health-related services. Conclusions: For school-aged children, a history of TBI is associated with parent-reported health needs and conditions, as well as missed days from school. It is particularly important for parents to seek care when they suspect their child has experienced a TBI to receive a diagnosis and monitor the impacts of the TBI. © 2024