This study explores how a long-running, special education teacher education-focused international immersion experience has grown over time to include robust international exchange between home and host institutions and how participation influenced past participants' professional practice. This research fills a gap in the research linking special education teacher preparation and international immersion experiences by focusing on a twenty-year-old immersion program which places preservice special education teachers in Scotland for a five-week experience including a homestay, school-based practicum, and travel. Researchers included two groups for this multiple case study design: Scottish school partners and preservice U.S. teacher participants. Interviews and reflections from each group were analyzed using the Relational-Cultural Theory framework to understand how this program grew and led to mutually beneficial partner and participant exchanges. Findings indicate that trusting relationships emanating from long-term interactions are key for meaningful exchange and that participation in the 2019 program influenced current teachers' professional decisions and trajectory.