Inclusion Criteria:  All patients admitted to Brigham and Women's and BWH Faulkner Hospitals and prescribed antibiotics with a stated indication of pneumonia who have a median respiratory rate of ≤20 and oxygen saturation of ≥95% without supplemental oxygen sustained for at least 24 hours.  Exclusion Criteria:  Patients under 18 years old, patients on transplant and oncology services, patients who are pregnant, patients in an intensive care unit, patients with cystic fibrosis or bronchiectasis, patients on immunosuppressive medications, and patients with positive blood cultures (other than common skin contaminants)