EPBO and APBO are not considered for pensions but “other postretirement benefits” like healthcare, welfare… I have a note stating that when using the income statement approach that it uses a similar treatment as pension (benefit of years service approach) where the EPBO is attributed to each year of service in attribution period. And that under SIR AGE (Becker people) that the current service cost is part of the EPBO arising from employee service in this period and that interest cost is the increase in APBO due to the passage of time (because as you get closer to the due date, the PV of the liability will increase, which is why you add to PBO/APBO) and = beginning APBO x discount rate. Pensions use the PBO for both calculations
Putting my definitions from Becker here:
PBO (pensions) – assumption of future salary (only) – actuarial PV of all benefits attributed based on service rendered prior to that date.
Accumulated Postretirement Benefit Obligation (APBO) – PV of future benefits have vested as of measurement date, discounted using an assumed discount rate. This rate is used to determine APBO, EPBO & the service & interest cost components of net periodic postretirement benefit cost
Expected Postretirement Benefit Obligation (EPBO) – PV of future benefits expected to be paid as of measurement date & includes: the amount that has vested (APBO) + PV of expected future benefits that have not yet vested.
…i'm glad this came up since i had erased the whole second set of notes assuming they were exactly the same!
.