NAS IS CLOSED: After 30 years, NAS has closed its doors. Thank you for entrusting us with you med-legal psychiatric evaluations. EFFECTIVE FEBRUARY 1, 2017 Established in 1986, National Assessment Specialists founded by Irwin Savodnik, M.D. is a psychiatric medical group that provides expert medical-legal evaluations in workers' compensation, disability, personal injury, fitness for duty, pre-surgical approval, competency and neuropsychological testing.