Many rehabilitation hospitals use formal measurement tools to evaluate program performance. A potential advantage to using the Functional Independence Measure™ instrument through the Uniform Data System for Medical Rehabilitation (UDSmr) is that it provides information that allows an institution to compare its level of performance to those of other facilities. To assess whether joining UDSmr, along with an institution's continuous quality improvement efforts, could be associated with improved program performance, the records of a rehabilitation hospital's internal inpatient Program Evaluation System (PES) were reviewed for 6 fiscal years (1990–1995). Quality improvement efforts during 1995 (during which a 51% improvement in length of stay efficiency was noted) included education for staff, feedback on team performance, and efforts to formulate clinical pathways. Although external measures of performance do not have a direct effect on quality improvement, they could help identify areas of potential improvement that might not be appreciated when internal assessment systems are used alone.