Objective Eating disorders typically onset in preadolescence and adolescence and cause negative mental and physical health sequelae over the life span. This study examined the incidence and medical hospitalization rates of pediatric eating disorders in an integrated health system in the United States. Methods This retrospective cohort study examined 4883 Kaiser Permanente Northern California members 8-18 years of age with an eating disorder diagnosis from January 2015 to June 2019. Medical hospitalizations include admissions at any of the 13 Kaiser Permanente Northern California hospitals with a primary or secondary eating disorder diagnosis. Results Incidence rates ranged between 177 and 205 per 100,000 adolescents per year. More than half the adolescents were non-White: 10.8% Asian, 4.3% Black, 26.7% Hispanic/Latinx, 8.4% multiracial, 0.3% Native American/Alaskan Native, and 0.5% Native Hawaiian/Pacific Islander. Thirteen percent had a body mass index (BMI) below the 5th percentile, 61.8% had a BMI between the 5th and the 84th percentiles, 19.7% had a BMI above the 85th percentile, and 5.6% had an unknown BMI. During the 12-month follow-up period, 5.4% of adolescents had medical hospitalizations. Conclusions This study adds to the evidence that eating disorders affect children/adolescents across all weight/BMI ranges and racial/ethnic backgrounds. Future studies call for exploration on treatment strategies that tailor to the diverse populations.