Schema modes are strong, predominant, momentary (state-like) emotional and cognitive states, and maladaptive coping responses that occur when underlying personality schemas are activated by emotional events. The current study employed the Schema Mode Inventory for Adolescents (SMI-A) to assess such schema modes in a sample of non-clinical adolescents (n = 530). Confirmatory factor analysis revealed that the hypothesized model of the SMI-A with 14 separate schema modes provided a good fit for the data. Reliability coefficients for the various schema modes were all in the adequate to good range. Finally, the validity of the SMI-A was supported by significant and meaningful relations between schema modes on the one hand and early maladaptive schema domains, symptoms of psychopathology, and quality of life on the other. Taken together, the psychometric properties of the SMI-A are promising, and the SMI-A can be considered a viable instrument to assess schema modes in adolescents.