Background <p>The increase in mental health disorders underscores the importance of preventive interventions and strategies. The approach of hybrid interventions integrating analog and common therapeutic approaches with digital health applications offers promising solutions but faces challenges in routine implementation. This study examines the implementation of the new hybrid intervention ‘RV Fit Mental Health’ within the German health care system, using Normalization Process Theory (NPT) as the guiding theoretical framework.</p> Methods <p>A qualitative study was conducted with nine experts involved in the development and implementation of the intervention, including professionals from the therapeutic and administrative domains of the implementation. Data were collected through semi-structured interviews and analyzed using qualitative content analysis, following the NPT framework and the NPT coding manual.</p> Results <p>The findings demonstrate that while the shift towards preventive care within the intervention required substantial organizational and normative adaptations, the intervention was largely perceived as a valuable and integrative addition in established care. Facilitating factors included stakeholder collaboration, a shared understanding of and goals for preventive care, and flexible, open organizational structures. Barriers and challenges were mainly linked to time and resource constraints, technical integration of the digital component, and the redefinition of professional roles. The implementation of the intervention reshaped therapeutic routines, fostered interdisciplinary collaboration, and was increasingly normalized within the specific conditions of a model project, both within clinical and administrative workflows and across organizational boundaries.</p> Conclusions <p>The implementation of the hybrid intervention RV Fit Mental Health was largely successful. The evaluation of the implementation of (hybrid) interventions benefits from a theory-driven approach. NPT provided valuable insights into how such interventions are embedded in existing systems and structures and how preventive and hybrid approaches can be sustainably integrated. The results offer both theoretical and practical implications for the design, implementation, and evaluation of similar interventions in diverse healthcare settings.</p> Trial Registration <p>DRKS-ID: DRKS00033080 (Date of registration: 07 December 2023)</p>