This study in Michigan explored whether SARS-CoV-2 vaccination decreased the rate of COVID-19 hospitalization and emergency care use. Adult patients presenting to emergency departments were separated into fully vaccinated (129), partially vaccinated (825) and unvaccinated groups (10,880). Fully vaccinated patients had a 96% lower rate of COVID-19 emergency department visits compared to the unvaccinated group (P< 0.001). Overall death rate was 3.7%; 384 of 10800 (3.5%) unvaccinated, 50 of 825 (6.1%) partially vaccinated, and 8 of 129 (6.2%) of the fully vaccinated died during the study period. All deaths in the fully vaccinated group were among patients over 65. Given the current SARS-CoV-2 variants, vaccination effectively reduces emergency use and hospitalization rate among the fully vaccinated population. Fully vaccinated adults who are hospitalized, while rare, tend to be older and with comorbidities.