Brain injury affects nearly 1.5 million people in the United States every year and estimated that 124,000 of those affected will have some form of long-term disability. Impaired Self Awareness (ISA) has been identified as one of the largest obstacles to successful brain injury rehabilitation and adaption to living with a brain injury. Research on the relationship between the awareness of individuals with acquired brain injury (IwABI) and their significant others has been inconsistent. This study examined the role IwABI and their significant others perception concordance&mdashagreement concerning functioning&mdashhas on maintenance of rehabilitation gains at a follow-up date after completion of adolescent brain injury rehabilitation services. Contrary to the hypotheses, the data showed a strong correlation (.872, p&le.01) and significant relationship (t=35, p&le.001) between IwABI and their significant others Functional Area Outcomes Menu (FAOM) scores at follow-up. There was no relationship between functioning at discharge and perception concordance at follow-up or time post-discharge and perception concordance at follow-up. Several explanations for the findings are provided along with suggestions for future investigation of the research subject.