The incremental costs of hospitalist care will be related to prevented hospital days from a healthcare system perspective following state-of-the-art guidelines. Hospital costs after admission to one of the 4 services (excluding any prior costs incurred in the emergency room [ER] or pediatric intensive care unit [ICU]) will be estimated using claims-based hospital charges multiplied by department-specific cost-to-charge ratios specified in the hospital's annual Medicare Cost Report. The costs will be inflated to 2018 U.S. dollars based on the Consumer Price Index for medical services. Physician costs will be estimated using a relative value unit (RVU)-based method. The resource-based RVU for each physician service provided during hospital days will be obtained from the medical school billing system and multiplied by the Medicare conversion factor. Costs for hospitalist care will be augmented to include any salary differentials and/or supplements received by hospitalists for taking more night shifts.