Study DesignProspective cohort study. IntroductionSome third-party payers require hand therapists to rate patient's functional disability based on patient self-rating using patient-reported outcome measures (PROMs), objective measurements of impairment, and observation of functional tasks—hand therapist–rated function (HTRF). Purpose of the StudyTo test the correlation between HTRF and PROMs (upper limb functional index [ULFI] and Patient-Reported Outcomes Measurement Information System upper extremity [PROMIS UE]) and its association with psychological factors. MethodsIn 2014, 100 new patients with upper extremity illness presenting to hand therapists were asked to participate in an observational cross-sectional study. Demographic-, condition-related, and psychological factors were obtained in addition to PROMs and HTRF. ResultsHTRF correlated moderately with PROMIS UE (r = −0.49, P < .001) and ULFI (r = −0.56, P < .001). Correlation between PROMIS UE and ULFI was strong (r = 0.78, P < .001). Psychological factors explained most of the variations in both HTRF and PROMs. ConclusionsHand therapists' ratings of patient function correlate less strongly with PROMs than PROMs correlate with one other. The discrepancy between HTRF and PROMs may offer an opportunity to address stress, distress, or ineffective coping strategies that can interfere with recovery—an opportunity for therapists and patients to collaborate and develop goals and for future research to develop effective and feasible strategies for hand therapists. Level of EvidenceLevel II, diagnostic study.