There are many factors to consider when treating adolescents with psychiatric challenges, including whether they are willing and interested in participating in treatment. This study aimed to explore how treatment readiness impacts treatment experience for adolescents in psychiatric residential care who came into treatment with moderate to severe depression. All participants (N = 1,624; Mage = 15.58, SD = 1.46) were admitted to a large, multi-state psychiatric residential system between January 2020 and March 2022. Patients were 95.6% White, 99% non-Hispanic, and 64.7% identified as female. At intake, all patients were administered an assessment which includes the multi-dimensional Behavioral Health Screen (BHS) that assesses psychopathology and risk factors, a working alliance scale, depression, and well-being measures. Patients were also asked how they were admitted to the program, using a single item, multiple choice question as an informal treatment readiness measure, yielding three readiness groups: precontemplation, contemplation, or preparation. Regression analysis results indicated that patients’ readiness level was associated with different baseline characteristics (e.g., age, gender, psychopathology symptoms, risk factors) and week 3 outcomes (e.g., decreased symptoms, well-being, alliance, satisfaction). The clinical implications, as well as limitations and future directions, will be discussed.