THIS 'MAKE-BUY' DECISION IS EXPLORED THROUGH DISCUSSION OF THE BASIC STEPS IN THE ANALYTICAL PROCESS FOR DETERMINING WHETHER IT IS MORE DESIRABLE TO 'MAKE' OR TO 'BUY' HEALTH SERVICES FOR PRISON RESIDENTS. DETAILED EXPLANATION IS GIVEN OF EACH OF SIX STEPS: (1) DEFINING THE PROBLEM AND STATING THE OBJECTIVES, (2) IDENTIFYING ALTERNATIVE SOLUTIONS, (3) IDENTIFYING DECISION VARIABLES FOR EACH ALTERNATIVE, (4) COLLECTING NECESSARY DATA, (5) SOLVING THE TOTAL COST FORMULA AND REVIEWING OBJECTIVES TO DETERMINE THE BEST ALTERNATIVE, AND (6) TESTING THE SENSITIVITY OF THE CHOICE MADE TO POSSIBLE ERRORS. THIS STEP-BY-STEP PROCESS IS THEN APPLIED TO AN EXAMPLE OF A HYPOTHETICAL PRISON DECIDING WHETHER TO MAKE OR TO BUY PHARMACY SERVICES; THIS EXAMPLE IS INTENDED AS AN ILLUSTRATION OF THE DECISION PROCESS AS THE PROCESS CAN BE USED FOR ANY HEALTH SERVICE BEING CONSIDERED. A FLOW CHART FURTHER ILLUSRATES THE STEP-BY-STEP PROCESS. A CHECKLIST OF POINTS TO REMEMBER IS PROVIDED. REFERENCES ARE INCLUDED.