ImportanceAutism and eating disorders cooccur at high rates, with autism impacting the efficacy of eating disorder treatments and outcomes. Females are underdiagnosed with autism and diagnosed later in life than their male counterparts.ObjectiveThe purpose of this study was to define the incidence of eating disorder professionals identifying autism in female adolescents and young adults engaged in treatment for an eating disorder.DesignThe research design is a cross-sectional retrospective records review. The charts reviewed were from the medical records of forty assigned-at-birth females between the ages of 13–25 who received treatment for an eating disorder at the partial hospitalization program (PHP) level of care between 2020 and 2022.Main outcomesUpon entering PHP for an eating disorder, 10% of the study participants had a pre-existing diagnosis of autism. A total of 27.5% of participants had clinical suspicion of autism. The number of autism traits that an individual possessed directly correlated with the number of calendar days in treatment.ConclusionEating disorder professionals in this study identified autism in 17.5% of adolescent and young adult females who entered PHP treatment for an eating disorder who had not previously been diagnosed with autism. Eating disorder professionals can anticipate that individuals with autism may be in treatment for a longer duration. Further studies should explore effective treatment measures for those with autism in treatment for an eating disorder.