1. Attribution 2. EPBO 3. Postretirement health care Discounted present value of total postretirement benefit costs. Discount rate times beginning APBO. Portion of the EPBO attributed to the current period. Process of assigning the cost of benefits to the years during which those benefits are assumed to be earned by employees. Related to need, not service. The portion of the EPBO attributed to employee service to date. 4. APBO (Postretirement) 5. Service cost 6. Interest cost