THE AVERAGE NUMBER OF MAN-DAYS PAID FOR JAIL, PRISON, PROBATION, AND PAROLE DURING THE CONTROL STUDY YEAR (1973-74) WAS COMPUTED ALONG WITH THE OPERATIONAL COSTS FOR EACH ACTIVITY AND THE COST PER DAY. ANALYSIS OF COST PER CASE DAY AND CASE YEAR FOR ELEVEN ARIZONA CORRECTIONAL FACILITIES SHOWED THAT PROBATION WAS THE LOWEST COST MODE OF REHABILITATION, FOLLOWED BY PAROLE, JAIL, PRISON, AND HALF-WAY HOUSES. IT WAS RECOMMENDED THAT AS MANY CONVICTED CRIMINALS AS POSSIBLE BE DIVERTED INTO A PROBATION PROGRAM, AND THAT SUCH PROGRAMS RECEIVE MUCH MORE FUNDING THAN IS CURRENTLY PROVIDED, BECOMING THE PRIMARY REHABILITATION VEHICLE. TABULAR DATA ON PRESENT COST AND POPULATION IS PRESENTED FOR ALL STUDIED METHODS OF INCARCERATION AND REHABILITATION.