Inclusion Criteria:  Participants are 12-18 years of age Participants live with a family (some families may contain only one parent) Family members fluently speak and read English and have access to a computer with internet Participants meet DSM-5 criteria for AN (both subtypes) IBW between 75% and 88% Participants are medically stable for outpatient treatment according to the recommended thresholds of the American Academy of Pediatrics and the Society of Adolescent Medicine Participants are not engaged in another individual or family based psychotherapy trial during the duration of treatment sessions in the study. Medications for comorbid psychiatric disorders are OK; randomization will balance groups through tracking.  Exclusion Criteria:  Associated physical illness that necessitates hospitalization Psychotic illness in any form, mental retardation, autism, or any other mental illness that would interfere with the use of psychotherapy. Current dependence on drugs or alcohol Physical conditions (e.g. diabetes mellitus, pregnancy) known to influence eating or weight Previous (5 or more sessions of) or current FBT-AN Participants and family members do not have an adequate understanding of spoken English and are not able to speak and read English in order to participate in family therapy and the assessments. Current weight is less than 75% or above 88% of expected weight given age and height.