FIVE SERVICE AREAS CAN OPERATE THROUGH DIFFERENT ORGANIZATIONAL ARRANGEMENTS: SCREENING, MEDICAL CARE, SOCIAL SERVICES, PSYCHOLOGICAL ASSISTANCE, AND REFERRAL. THE MODEL EMBRACING THESE SERVICE AREAS HAS FOUR ALTERNATIVE ORGANIZATIONAL SYSTEMS. IN THE INTERNAL SYSTEM, ALL SERVICES TO INMATES ARE ADMINISTERED AND PROVIDED TO INMATES BY HUMAN SERVICE AGENCIES ADMINISTERED SEPARATELY AND NOT AS PART OF THE JAIL PROGRAM. THE LINKAGE SYSTEM IS AN INTERORGANIZATIONAL SCHEME IN WHICH ONE NONJAIL AGENCY OPERATES IN THE JAIL AND TAKES ON PRIMARY SERVICE RESPONSIBILITY BY ACTING IN A GENERAL CASE-FINDING CAPACITY. THE COMBINATION SYSTEM CONSISTS OF TWO OR MORE TYPES OF SERVICES. AS JAILS DEVELOP INTO MULTIPURPOSE, DUAL GOAL ORGANIZATIONS, THE PRIORITY GOAL OF CUSTODY AND THE TREATMENT OR REHABILITATION NEEDS OF INMATES HAVE HAD A POSITIVE IMPACT ON THE FULFILLMENT OF THE CUSTODIAL OBJECTIVE. ALTHOUGH APPROXIMATELY HALF OF THE JAILS HAVE INTERNAL SYSTEMS, PRESSURES FOR EXPANDED INMATE SERVICES HAVE SLOWLY PRODUCED SOME USE OF OTHER ORGANIZATIONAL STRUCTURES. SYSTEMS OF THE MODEL OF JAIL SERVICE DELIVERY ARE DESCRIBED IN A TABLE THAT INCLUDES ILLUSTRATIONS. REFERENCES ARE CITED. (DEP)