PURPOSE OF THE STUDY To examine the components of cost that drive increased total costs after a medical fall over time, stratified by injury severity. DESIGN AND METHODS We used 2004-2007 cost and utilization data for persons enrolled in an integrated care delivery system. We used a longitudinal cohort study design, where each individual provides 2-3 years of administrative data grouped into 3-month intervals relative to an index date. We identified 8,969 medical fallers through International Classification of Diseases, 9th Revision, codes and E-Codes and used 8,956 nonfaller controls, identified through age and gender frequency matching. Total costs were partitioned into 7 components: inpatient, outpatient, emergency, radiology, pharmacy, postacute care, and "other." RESULTS The large increase in costs after a hospitalized fall is mainly associated with inpatient and postacute care components. The spike in costs after a nonhospitalized fall is attributable to outpatient and "other" (e.g., ambulatory surgery or community health services) components. Hospitalized fallers' inpatient, emergency, postacute care, outpatient, and radiology costs are not always greater than those for nonhospitalized fallers. IMPLICATIONS Components associated with increased costs after a medical fall vary over time and by injury severity. Future studies should compare if delivering certain acute and postacute health services improve health and reduce cost trajectories after a medical fall more than others. Additionally, since the older adult population and the problem of falls are growing, health care delivery systems should develop standardized methodology to monitor medical fall rates.