BACKGROUND: Immigration inadmissibility on medical grounds is common among high-income countries. In Canada, the Immigrant and Refugee Protection Act (IRPA) became law in 2002. With humanitarian protection as a priority, IRPA removed medical inadmissibility based on exceeding a cost threshold for the projected use of health and social services for resettled refugees. Our objective was to determine whether resettled refugees arriving in Ontario after IRPA became law (2004-2017) were more likely to exceed the cost threshold than those who arrived before (1994-2002). METHODS: We linked population-based immigration (1994-2017) and healthcare data (1994-2019) in Ontario, Canada and conducted interrupted and controlled interrupted time series (ITS and CITS, respectively) analyses using segmented regression. We examined morbidity prevalence (a proxy for exceeding the cost threshold), in the pre-IRPA and post-IRPA periods among resettled refugees and three control groups-successful asylum seekers, economic immigrants and other Ontario residents. Morbidity prevalence levels and slopes across years were estimated comparing the post-IRPA to pre-IRPA period within resettled refugees and each control group (ITS), and for resettled refugees relative to each control group comparing the same periods (CITS). RESULTS: Morbidity prevalence levels and slopes did not increase significantly within resettled refugees arriving after compared with before IRPA, nor when compared with control groups. Increasing morbidity prevalence among all immigrant groups post-IRPA suggested that subsequent policy changes linked to excessive demand policies may have impacted morbidity. CONCLUSION: Evolving medical inadmissibility policies suggest the need to provide a fulsome evaluation, balancing possible implications with the documented contributions immigrants make to Canada.