Hospital-based ambulance services are one of multiple models for providing ambulance services in rural communities. This model has not been extensively studied. Critical Access Hospitals (CAHs) may own or operate ambulance services directly, as a stand-alone entity owned, or be contractually controlled by the hospital. The Flex Monitoring Team at the University of Southern Maine conducted a mixed methods study to address the extent to which CAHs do so, identifying trends in the number of CAH-based ambulance services using 2017 to 2022 Medicare Cost Report data and comparing the characteristics (e.g., location, ownership, and financial) of CAHs that own or operate ambulance services to CAHs that do not. Additionally, data collected through qualitative interviews with eight CAH-based ambulance services, including ambulance directors and hospital administrators, highlighted the challenges of operating these services, workforce recruitment and retention issues, the role of partnerships and community involvement, and lessons learned. The results of this study will provide useful information to State Flex Programs (SFPs) seeking to improve the performance of CAH-based ambulance services in their states and/or explore the use of the model to expand access to ambulance services in rural communities.