In this study, we measure the concurrent validity of administering the Functional Independence Measure instrument by interview. Data from 28 community-dwelling, cognitively intact, elderly patients with hip fracture were collected in 5 postacute rehabilitation facilities. Within 72 hrs of admission to (and at discharge from) the postacute facilities, both a Functional Independence Measure-certified interviewer and a multidisciplinary team administered the Functional Independence Measure instrument to each participant concurrently. At admission, the mean Functional Independence Measure ratings assigned by the interviewer and by the team were 84.3 and 80.5, respectively (P < 0.001). At discharge, the mean Functional Independence Measure ratings were 104.4 and 103.4 (P > 0.50), reflecting the participants' functional recovery during postacute rehabilitation. The intraclass correlation between the Functional Independence Measure ratings assigned by the interviewer and by the team was 0.74 (95% confidence interval = 0.58-0.91) at admission and 0.76 (95% confidence interval = 0.60-0.92) at discharge. Functional Independence Measure ratings assigned by Functional Independence Measure-certified interviewers are valid indicators of the functional status of groups of older people recovering from hip fracture and feasible for longitudinal study.