The Mayo-Portland Adaptability Inventory – version 4 (MPAI-4) assesses deficits, activities and participation in individuals with acquired brain injury in rehabilitation programs. The single subscale measuring participation, the Participation Index (M2PI), can be used by itself. The training materials have primarily been developed for the use of the MPAI-4 and M2PI in stroke outpatient programs; however, the information could be applicable across all acquired brain injury rehabilitation.