Floods are increasing with climate change, and evacuating medically vulnerable people receiving home healthcare remains challenging. Patients dependent on medical devices and long-term care face complex challenges throughout the evacuation process. However, key factors influencing successful evacuation and effective support strategies remain underexamined. This study aimed to identify such factors and essential support measures across evacuation phases.

Semi-structured interviews were conducted with 13 participants—family caregivers, healthcare providers, and municipal officials—from July 2022 to March 2023 in 3 Japanese regions. Snowball sampling was used via medical administrative institutions. Thematic analysis followed COREQ guidelines, focusing on three phases: preparation, evacuation, and post-evacuation. Ethics approval was obtained (MG2022-01).

Preparation showed heterogeneous readiness: some services had hazard maps and manuals/BCPs, whereas household engagement was limited and operationalization was constrained by resources. During evacuation, participants described transport and staffing limitations, difficulty in moving medical equipment, and uncertainty about feasible options, with occasional consideration of vertical evacuation. Post-evacuation challenges centered on shelter sanitation and supplies, continuity of medical support, and coordination of support systems.

A three-phase, multi-stakeholder perspective clarifies how constraints accumulate and informs coordinated planning among municipalities, home-care teams, and families. Limitations include a small, region-specific sample and no direct patient interviews.