| | Total | | Principal | | Other | | Retiree |
| | postretirement | | pension | | pension | | benefit |
| (In millions) | benefit plans | | plans | | plans | | plans |
| | | | | | | | | | | | |
| Cost of postretirement benefit plans | $ | 5,977 | | $ | 4,405 | | $ | 645 | | $ | 927 |
| Changes in other comprehensive income | | | | | | | | | | | |
| Prior service cost – current year | | 11 | | | - | | | 11 | | | - |
| Net actuarial gain – current year(a) | | (12,263) | | | (9,218) | | | (1,151) | | | (1,894) |
| Prior service cost amortization | | (646) | | | (246) | | | (7) | | | (393) |
| Net actuarial gain (loss) amortization | | (3,962) | | | (3,664) | | | (343) | | | 45 |
| Total changes in other comprehensive income | | (16,860) | | | (13,128) | | | (1,490) | | | (2,242) |
| Cost of postretirement benefit plans and | | | | | | | | | | | |
| changes in other comprehensive income | $ | (10,883) | | $ | (8,723) | | $ | (845) | | $ | (1,315) |
| | | | | | | | | | | | |
