Advance care planning conversations in home care: Intervention development with the Behaviour Change Wheel Abstract. Background: StAdPlan is a multicenter, cluster-randomized controlled trial aimed to develop and evaluate an advance care planning (ACP) intervention for the German home care setting. Aim: This paper reports the intervention development. Available ACP concepts were reviewed and adapted to the German home care context in terms of staffing and available time resources. Skilled nurses are assigned to raise the awareness on ACP among older care-dependent people and their informal caregivers/relatives through structured conversation and facilitating the use of existing counselling services. Methods: The Behavior Change Wheel (BCW) was applied to the development of the intervention components. Results: The complex intervention addresses care-dependent people aged 65 years and above and their informal caregivers. A two-day training session qualifies nursing professionals to offer guideline-based conversations which take place at least twice at the care-dependent person's home, if possible with the involvement of relatives. An additional information brochure is provided. Conclusions: The application of the BCW model proved to be appropriate for the analysis, description and definition of the specific functions of the intervention. The intervention is prepared for the effectiveness study.