Throughout the course of the pandemic in Missouri, patients have benefited from marked improvement in clinical understanding and treatment of COVID-19, thus reducing both length of stay and mortality for COVID-19 patients. At the same time, the clinical acuity and complexity of COVID-19 patients in Missouri have remained relatively stable. Between April and June, COVID-19 patients in Missouri were hospitalized for 9.7 days on average. Between July and September, the average length of stay fell to 7.5 days, a 23% reduction, which has been critical in freeing up scarce resources such as inpatient and ICU beds, particularly during the November surge in cases and hospitalizations. Additionally, between April and June, 16% of Missouri COVID-19 patients died during their hospitalization. Between July and September, the mortality rate fell to 9.8%, a 39% reduction. During the same period, the risk-adjusted ALOS that accounts for patients’ age, demographic characteristics, social determinants of health and clinical comorbidities decreased by just one-half day. This suggests that the improvement in ALOS and mortality have been a result of improved clinical effectiveness and not changes in the underlying risk factors of COVID-19 patients.