BACKGROUND: The economic burden of food allergy is large; however, costs specific to individuals with peanut allergy experiencing reactions to peanuts remain to be evaluated. As the prevalence of peanut allergy continues to increase in children, a better understanding of the cost of care is warranted. OBJECTIVE: To assess the cost of care of peanut allergy among privately insured and Medicaid-insured pediatric patients in the United States. METHODS: This retrospective matched-cohort study included patients aged 4-17 years from the Optum Health Care Solutions and Medicaid Claims databases (January 1, 2007-March 31, 2017). Patients were classified into 2 cohorts: peanut allergy (with peanut allergy diagnosis codes and reactions triggering health care resource utilization [HRU]) and peanut allergy-free (no peanut allergy diagnosis codes in claims). Peanut allergy patients were matched 1:10 to peanut allergy-free patients based on baseline covariates. Comorbidities including anxiety and depression, HRU, and direct health care costs were compared between cohorts and reported for both perspectives separately. RESULTS: Compared with peanut allergy-free patients (n = 30,840 privately insured; n = 12,450 Medicaid), peanut allergy patients (n = 3,084 privately insured; n = 1,245 Medicaid) had higher prevalence of asthma, atopic dermatitis/eczema, other food allergies, allergic rhinitis, depression, and anxiety (all P < 0.01). Peanut allergy patients had higher HRU per patient per year (PPPY), including 90% more emergency department visits among both privately insured and Medicaid patients (P < 0.01) and higher direct health care costs PPPY, with incremental costs of $2,247 total or $1,712 excluding asthma-related costs for privately insured patients and $2,845 total or $1,844 excluding asthma-related costs for Medicaid patients (all P < 0.01). CONCLUSIONS: Pediatric patients in the United States with peanut allergy and reactions triggering HRU had significantly higher comorbidity burdens, HRU, and direct health care costs, regardless of asthma-related costs, versus those without peanut allergy. DISCLOSURES: This study was funded by Aimmune Therapeutics, a Nestlé Health Science company. The study sponsor was involved in several aspects of the research including the study design, the interpretation of data, the writing of the manuscript, and the decision to submit the manuscript for publication. Yu and Tilles are employees of Aimmune Therapeutics, a Nestlé Health Science company. Robison and Norrett were employees of Aimmune Therapeutics at the time this study was conducted. Blaiss, Meadows, and Hass provided paid consulting services to Aimmune Therapeutics. Guerin and Latremouille-Viau are employees of Analysis Group, a consulting company that provided paid consulting services to Aimmune Therapeutics. Parts of the results were presented at the AMCP Managed Care & Specialty Pharmacy Annual Meeting held March 25-28, 2019, in San Diego, CA, and at the ISPOR Annual Meeting held May 18-22, 2019, in New Orleans, LA.