OBJECTIVE:This study tested clinical utility of the DSM-5 severity specifier for bulimia nervosa (BN) in predicting treatment response among adolescents (N = 110) within a randomized clinical trial of two psychosocial treatments. METHOD:Analyses grouped individuals meeting criteria for BN diagnosis by baseline severity, per DSM-5. Associations among baseline severity classification and BN behavior (i.e., binge eating and compensatory behavior) and eating disorder examination (EDE) Global scores at end-of-treatment (EOT), 6- and 12-month follow-up were examined. RESULTS:Associations between severity categories with BN symptoms were not significant at EOT, or follow-up. Test for linear trend in BN behavior was significant at EOT, F = 5.23, p = 0.02, without demonstrating a linear pattern. Relation between severity categories with EDE Global scores was significant at 6-month follow-up, F = 3.76, p = 0.01. Tests for linear trend in EDE Global scores were significant at EOT, F = 5.40, p = 0.02, and at 6 months, F = 10.73, p = 0.002, with the expected linear pattern. DISCUSSION:Findings suggest the DSM-5 BN severity specifier holds questionable utility in anticipating outpatient treatment response in adolescents with BN. The specifier may have improved ability to predict attitudinal rather than behavioral treatment outcomes.