Background: This article presents the conceptual principles as well as the clinical implications of a research-based transtheoretical treatment and training model (4TM) that can provide the foundation for future evidence-based and personalized psychotherapeutic practice as well as training and continuing education in psychotherapy. Objective: Derivation and presentation of a scientifically based open transtheoretical framework model for psychotherapeutic practice as well as training and continuing education in psychotherapy. Method: The model incorporates findings from the psychotherapy research on differential treatment results, feedback research, research on differences between therapists as well as research on alteration processes and modern technical developments in an open conceptual framework model for the clinical practice and training. Results: The model is based on interventions that trigger alteration processes at behavioral, cognitive, emotional, motivation-related, interpersonal, and systemic/sociocultural levels in patients. Additionally, the 4TM incorporates a data-driven decision support and feedback system called the Trier treatment navigator (TTN). Discussion: Important problems of a strictly school-based approach of psychotherapy in Germany are discussed and these are compared with the open framework of a research, feedback, and process-oriented concept as a guide for transtheoretical interventions. This concept can provide an orientation for a scientifically based psychotherapy, taking traditional and emerging clinical developments and insights from psychotherapy research into account. It can be flexibly adapted to diverse patient populations in a culturally sensitive manner.