Importance Pediatric behavioral health conditions are common and may confer substantial health care costs and financial strain on families. Objective To quantify 2022 US pediatric behavioral health care expenditures, evaluate 2011 to 2022 changes in expenditures, and examine the association between child behavioral health spending and family financial burden. Design, Setting, and Participants Cross-sectional study of US children aged 6 to 17 years, using 2011-2022 Medical Expenditure Panel Survey household component files, with analysis performed from January 11, 2024, to October 15, 2025. Exposure Expenditure trends analysis included year. Family financial burden analysis included child behavioral health spending. Main Outcomes and Measures Behavioral health care and overall pediatric health care spending was totaled for 2022, using survey-weighted linear regression models to estimate trends. The association between child behavioral health spending and high family financial burden (sliding-scale income-based threshold) and extreme financial burden (&gt;10% of income) was evaluated with weighted logistic regression. Analyses were inflation adjusted. Results Pediatric behavioral health care expenditures in 2022 totaled $41.8 billion (95% CI, $17.0-$66.7 billion). The proportion of pediatric care expenditures for behavioral health increased from 22.4% in 2011 to 40.2% in 2022. Simultaneously, pediatric behavioral health out-of-pocket spending increased from $2.1 to $2.9 billion, by 6.4% annually (95% CI, 3.5%-9.0%). For families with at least 1 child with behavioral health spending, 12.5% of out-of-pocket spending among families with high financial burden and 14.4% of out-of-pocket spending among families with extreme financial burden were for child behavioral health care. Having a child with behavioral health spending was associated with high family financial burden (adjusted odds ratio, 1.60; 95% CI, 1.44-1.78) and extreme family financial burden (adjusted odds ratio, 1.42; 95% CI, 1.22-1.65). Conclusions and Relevance Behavioral health expenditures nearly doubled to 40% of US child health spending by 2022. Behavioral health spending was associated with high family financial burden, which reflects increased demand and cost for services and supports expanding access through insurance coverage and clinician availability.