The four systems are: (1) demographic variables, (2) Megargee Typologies, (3) Security Designation, and (4) Custody Classification. Data on 337 male inmates' adjustment as measured by four criterion variables of (a) number of disciplinary reported received, (b) days spent in disciplinary segregation, (c) days of statutory good time forfeited, and (d) work performance ratings were obtained and analyzed in relation to the four classification systems. Results of a canonical correlation procedure indicate that Custody Classification was the single best predictor of overall inmate adjustment with the demographic variable of age a distant second best. Using a stepwise multiple regression, each of the four measures of inmate adjustment was examined separately. Results revealed Custody Classification and inclusion in three of the ten Megargee Typologies to be the most effective single predictors. Recommendation for establishing a classificatory formula based on these variables is made with emphasis placed on the benefits of such a system. (Publisher abstract)