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Benefit Plans Benefit Plans (Tables) | 12 Months Ended
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Sep. 30, 2020
Retirement Benefits [Abstract] |
Obligations and Funded Status | The changes in plan obligations, assets, and funded status for the years ended September 30, 2020 and 2019, were as follows:
Obligations and Funded Status For the years ended September 30
795,900,000 |  | Pension Benefits |  | Other Post-Retirement Benefits
| 2020 |  | 2019 |  | 2020 |  | 2019
Change in benefit obligation |  |  |  |  |  |  |
Benefit obligation at beginning of year | $ | 13,312 |  |  | $ | 11,725 |  |  | $ | 499 |  |  | $ | 428 |
Service cost | 55 |  |  | 44 |  |  | 16 |  |  | 11 |
Interest cost | 415 |  |  | 499 |  |  | 16 |  |  | 18 |
Plan participants' contributions | 6 |  |  | 7 |  |  | — |  |  | — |
Collections(1) | — |  |  | — |  |  | 20 |  |  | 22 |
Actuarial (gain) loss | 614 |  |  | 1,756 |  |  | 39 |  |  | 78 |
Plan change | 2 |  |  | 7 |  |  | — |  |  | — |
Net transfers (to) from variable fund/401(k) plan | 2 |  |  | 1 |  |  | — |  |  | — |
Expenses paid | (5) |  |  | (6) |  |  | — |  |  | — |
Benefits paid | (726) |  |  | (721) |  |  | (46) |  |  | (58) |
Benefit obligation at end of year | 13,675 |  |  | 13,312 |  |  | 544 |  |  | 499 |
Change in plan assets |  |  |  |  |  |  |
Fair value of net plan assets at beginning of year | 7,980 |  |  | 8,003 |  |  | — |  |  | — |
Actual return on plan assets | 397 |  |  | 389 |  |  | — |  |  | — |
Plan participants' contributions | 6 |  |  | 7 |  |  | — |  |  | — |
Collections(1) | — |  |  | — |  |  | 20 |  |  | 22 |
Net transfers (to) from variable fund/401(k) plan | 2 |  |  | 1 |  |  | — |  |  | — |
Employer contributions | 305 |  |  | 307 |  |  | 26 |  |  | 36 |
Expenses paid | (5) |  |  | (6) |  |  | — |  |  | — |
Benefits paid | (726) |  |  | (721) |  |  | (46) |  |  | (58) |
Fair value of net plan assets at end of year | 7,959 |  |  | 7,980 |  |  | — |  |  | — |
Funded status | $ | (5,716) |  |  | $ | (5,332) |  |  | $ | (544) |  |  | $ | (499) |
Note (1) Collections include retiree contributions as well as provider discounts and rebates.
Amounts Recognized on TVA's Consolidated Balance Sheets | Amounts related to these benefit plans recognized on TVA's Consolidated Balance Sheets consist of regulatory assets and liabilities that have not been recognized as components of net periodic benefit cost at September 30, 2020 and 2019, and the funded status of TVA's benefit plans, which are included in Accounts payable and accrued liabilities and Post-retirement and post-employment benefit obligations:
Amounts Recognized on TVA's Consolidated Balance Sheets At September 30
| Pension Benefits |  | Other Post-Retirement Benefits
| 2020 |  | 2019 |  | 2020 |  | 2019
Regulatory assets (liabilities) | $ | 5,115 |  |  | $ | 4,731 |  |  | $ | 78 |  |  | $ | 25 |
Accounts payable and accrued liabilities | (5) |  |  | (5) |  |  | (28) |  |  | (28) |
Pension and post-retirement benefit obligations(1) | (5,711) |  |  | (5,327) |  |  | (516) |  |  | (471) |
Note (1) The table above excludes $390 million and $383 million of post-employment benefit costs that are recorded in Post-retirement and post-employment benefit obligations on the Consolidated Balance Sheets at September 30, 2020 and 2019, respectively.
Post-Retirement Benefit Costs Deferred as Regulatory Assets | Unrecognized amounts included in regulatory assets or liabilities yet to be recognized as components of accrued benefit cost at September 30, 2020 and 2019, consisted of the following:
Post-Retirement Benefit Costs Deferred as Regulatory Assets (Liabilities) At September 30
| Pension Benefits |  | Other Post-Retirement Benefits
| 2020 |  | 2019 |  | 2020 |  | 2019
Unrecognized prior service credit | $ | (615) |  |  | $ | (714) |  |  | $ | (112) |  |  | $ | (135) |
Unrecognized net loss | 5,620 |  |  | 5,350 |  |  | 190 |  |  | 160 |
Amount capitalized due to actions of regulator | 110 |  |  | 95 |  |  | — |  |  | — |
Total regulatory assets (liabilities) | $ | 5,115 |  |  | $ | 4,731 |  |  | $ | 78 |  |  | $ | 25 |
Projected Benefit Obligations and Accumulated Benefit Obligations in Excess of Plan Assets | The projected benefit obligation, accumulated benefit obligation, and fair value of plan assets for the pension plan at September 30, 2020 and 2019, were as follows:
Projected Benefit Obligations and Accumulated Benefit Obligations in Excess of Plan Assets At September 30
| 2020 |  | 2019
Projected benefit obligation | $ | 13,675 |  |  | $ | 13,312 |
Accumulated benefit obligation | 13,613 |  |  | 13,246 |
Fair value of net plan assets | 7,959 |  |  | 7,980 |
Components of Net Periodic Benefit Cost | The components of net periodic benefit cost and other amounts recognized as changes in regulatory assets for the years ended September 30, 2020, 2019, and 2018 were as follows:
Components of Net Periodic Benefit Cost For the years ended September 30
| Pension Benefits |  | Other Post-Retirement Benefits
| 2020 |  | 2019 |  | 2018 |  | 2020 |  | 2019 |  | 2018
Service cost | $ | 55 |  |  | $ | 44 |  |  | $ | 53 |  |  | $ | 16 |  |  | $ | 11 |  |  | $ | 14 |
Interest cost | 415 |  |  | 499 |  |  | 473 |  |  | 16 |  |  | 18 |  |  | 19 |
Expected return on plan assets | (488) |  |  | (477) |  |  | (478) |  |  | — |  |  | — |  |  | — |
Amortization of prior service credit | (97) |  |  | (99) |  |  | (99) |  |  | (24) |  |  | (24) |  |  | (22) |
Recognized net actuarial loss | 436 |  |  | 336 |  |  | 409 |  |  | 10 |  |  | 4 |  |  | 8 |
Total net periodic benefit cost as actuarially determined | 321 |  |  | 303 |  |  | 358 |  |  | 18 |  |  | 9 |  |  | 19 |
Amount expensed (capitalized) due to actions of regulator | (15) |  |  | 1 |  |  | (54) |  |  | — |  |  | — |  |  | — |
Net periodic benefit cost | $ | 306 |  |  | $ | 304 |  |  | $ | 304 |  |  | $ | 18 |  |  | $ | 9 |  |  | $ | 19 |
Expected Amortization of Regulatory Assets in Next Fiscal Year | The amounts in the regulatory asset that are expected to be recognized as components of net periodic benefit cost during the next fiscal year are as follows:
Expected Amortization of Regulatory Assets in 2021 At September 30, 2020
| Pension Benefits |  | Other Post-Retirement Benefits |  | Total
Prior service credit | $ | (97) |  |  | $ | (18) |  |  | $ | (115) |
Net actuarial loss | 447 |  |  | 12 |  |  | 459 |
Amounts expensed due to actions of regulator | 28 |  |  | — |  |  | 28 |
Actuarial Assumptions |
Actuarial Assumptions Utilized to Determine Benefit Obligations at September 30
| Pension Benefits |  | Other Post-Retirement Benefits
| 2020 |  | 2019 |  | 2020 |  | 2019
Discount rate | 2.75% |  | 3.20% |  | 3.05% |  | 3.30%
Rate of compensation increase | 3.43% |  | 3.50% |  | N/A |  | N/A
Cost of living adjustment (COLA)(1) | 2.00% |  | 2.00% |  | 2.00% |  | 2.00%
Pre-Medicare eligible |  |  |  |  |  |  |
Current health care cost trend rate(2) | N/A |  | N/A |  | 6.50% |  | 6.75%
Ultimate health care cost trend rate | N/A |  | N/A |  | 5.00% |  | 5.00%
Year ultimate trend rate is reached | N/A |  | N/A |  | 2027 |  | 2027
Post-Medicare eligible |  |  |  |  |  |  |
Current health care cost trend rate | N/A |  | N/A |  | —% |  | —%
Ultimate health care cost trend rate | N/A |  | N/A |  | 4.00% |  | 4.00%
Year ultimate trend rate is reached | N/A |  | N/A |  | 2024 |  | 2023
Notes (1) The COLA assumption is the ultimate long-term rate. The calendar year rate for 2021 is assumed to be one percent, and for years thereafter the ultimate is used. (2) In 2019, TVA reset the pre-Medicare health care cost trend rates assumption with an initial rate of 6.75 percent, declining 0.25 percent per year until it reaches the ultimate rate of 5.00 percent in 2027. For 2020, TVA maintained this trend assumption for pre-Medicare per capita claims cost with a current health care cost rate of 6.50 percent. However, to account for cumulative delayed medical care due to the COVID-19 pandemic and the expected spending as the demand for care returns, the pre-Medicare per capita retiree contributions current health care cost trend rate is 11.93 percent, and in 2022 assumed to return to 6.25 percent in line with the health care cost trend rates assumption.
Actuarial Assumptions Utilized to Determine Net Periodic Benefit Cost for the Years Ended September 30(1)
| Pension Benefits |  | Other Post-Retirement Benefits
| 2020 |  | 2019 |  | 2018 |  | 2020 |  | 2019 |  | 2018
Discount rate | 3.20 | % |  | 4.35 | % |  | 3.85 | % |  | 3.30 | % |  | 4.40 | % |  | 3.95 | %
Expected return on plan assets(2) | 6.75 | % |  | 6.75 | % |  | 6.75 | % |  | N/A |  | N/A |  | N/A
Cost of living adjustment (COLA)(3) | 2.00 | % |  | 2.00 | % |  | 2.00 | % |  | 2.00 | % |  | 2.00 | % |  | 2.00 | %
Rate of compensation increase | 3.43 | % |  | 3.50 | % |  | 5.34 | % |  | N/A |  | N/A |  | N/A
Pre-Medicare eligible |  |  |  |  |  |  |  |  |  |  |
Current health care cost trend rate | N/A |  | N/A |  | N/A |  | 6.75 | % |  | 6.25 | % |  | 6.50 | %
Ultimate health care cost trend rate | N/A |  | N/A |  | N/A |  | 5.00 | % |  | 5.00 | % |  | 5.00 | %
Year ultimate trend rate is reached | N/A |  | N/A |  | N/A |  | 2027 |  | 2024 |  | 2024
Post-Medicare eligible |  |  |  |  |  |  |  |  |  |  |
Current health care cost trend rate | N/A |  | N/A |  | N/A |  | — | % |  | — | % |  | — | %
Ultimate health care cost trend rate | N/A |  | N/A |  | N/A |  | 4.00 | % |  | 4.00 | % |  | 4.00 | %
Year ultimate trend rate is reached | N/A |  | N/A |  | N/A |  | 2023 |  | 2021 |  | 2021
Notes (1) The actuarial assumptions used to determine the benefit obligations at September 30 of each year are subsequently used to determine net periodic benefit cost for the following year except the rate of compensation increase assumption. (2) The actual return on assets for 2020, 2019, and 2018 were 5.11%, 4.99%, and 5.84%, respectively. (3) The COLA assumption is the ultimate rate. The actual calendar year rate is used in determining the expense, and for years thereafter the ultimate rate is used.
Sensitivity to Certain Changes in Pension Assumptions | The following chart reflects the sensitivity of pension cost to changes in certain actuarial assumptions:
Sensitivity to Certain Changes in Pension Assumptions At September 30, 2020
Actuarial Assumption |  | Change in Assumption |  | Impact on 2020 Pension Cost |  | Impact on 2020 Projected Benefit Obligation
Discount rate |  | (0.25) | % |  | $ | 17 |  |  | $ | 418 |
Rate of return on plan assets |  | (0.25) | % |  | 18 |  |  | N/A
Cost of living adjustments |  | 0.25 | % |  | 30 |  |  | 270 |
Sensitivity to Changes in Assumed Health Care Cost Trend Rates | The following chart reflects the sensitivity of post-retirement benefit cost to changes in the health care trend rate:
Sensitivity to Changes in Assumed Health Care Cost Trend Rates At September 30, 2020
| 1% Increase |  | 1% Decrease
Effect on total of service and interest cost components for the year | $ | 4 |  |  | $ | (4) |
Effect on end-of-year accumulated post-retirement benefit obligation | 70 |  |  | (68) |
Asset Holdings and Fair Value Measurements | s consistent with the asset allocation policy. At September 30, 2020 and 2019, the asset holdings of TVARS included the following:
Asset Holdings of TVARS At September 30
|  |  |  | Plan Assets at September 30
Asset Category |  | Target Allocation |  | 2020 |  | 2019
Global public equity |  | 32 | % |  | 36 | % |  | 37 | %
Private equity |  | 8 | % |  | 13 | % |  | 10 | %
Safety oriented fixed income |  | 20 | % |  | 18 | % |  | 18 | %
Opportunistic fixed income |  | 20 | % |  | 15 | % |  | 12 | %
Public real assets |  | 10 | % |  | 10 | % |  | 15 | %
Private real assets |  | 10 | % |  | 8 | % |  | 8 | %
Total |  | 100 | % |  | 100 | % |  | 100 | %
Fair Value Measurements The following table provides the fair value measurement amounts for assets held by TVARS at September 30, 2020:
TVA Retirement System At September 30, 2020
| Total(1)(2) |  | Quoted Prices in Active Markets for Identical Assets/Liabilities (Level 1) |  | Significant Other Observable Inputs (Level 2) |  | Significant Unobservable Inputs (Level 3)
Assets |  |  |  |  |  |  |
Equity securities | $ | 1,624 |  |  | $ | 1,621 |  |  | $ | — |  |  | $ | 3 |
Preferred securities | 11 |  |  | — |  |  | 11 |  |  | — |
Debt securities |  |  |  |  |  |  |
Corporate debt securities | 1,421 |  |  | — |  |  | 1,418 |  |  | 3 |
Residential mortgage-backed securities | 317 |  |  | — |  |  | 314 |  |  | 3 |
Debt securities issued by U.S. Treasury | 701 |  |  | 701 |  |  | — |  |  | — |
Debt securities issued by foreign governments | 231 |  |  | — |  |  | 179 |  |  | 52 |
Asset-backed securities | 116 |  |  | — |  |  | 88 |  |  | 28 |
Debt securities issued by state/local governments | 23 |  |  | — |  |  | 23 |  |  | — |
Commercial mortgage-backed securities | 91 |  |  | — |  |  | 86 |  |  | 5 |
Commingled funds measured at net asset value(3) |  |  |  |  |  |  |
Equity | 931 |  |  | — |  |  | — |  |  | — |
Debt | 203 |  |  | — |  |  | — |  |  | — |
Blended | 102 |  |  | — |  |  | — |  |  | — |
Institutional mutual funds | 277 |  |  | 277 |  |  | — |  |  | — |
Cash equivalents and other short-term investments | 338 |  |  | 77 |  |  | 261 |  |  | — |
Private credit measured at net asset value(3) | 166 |  |  | — |  |  | — |  |  | — |
Private equity measured at net asset value(3) | 1,003 |  |  | — |  |  | — |  |  | — |
Private real assets measured at net asset value(3) | 629 |  |  | — |  |  | — |  |  | — |
Securities lending collateral | 167 |  |  | — |  |  | 167 |  |  | — |
Derivatives |  |  |  |  |  |  |
Futures | 3 |  |  | 3 |  |  | — |  |  | — |
Swaps | 10 |  |  | — |  |  | 10 |  |  | — |
Options | 2 |  |  | — |  |  | 2 |  |  | — |
Foreign currency forward receivable | 2 |  |  | — |  |  | 2 |  |  | — |
Total assets | $ | 8,368 |  |  | $ | 2,679 |  |  | $ | 2,561 |  |  | $ | 94 |
Liabilities |  |  |  |  |  |  |
Derivatives |  |  |  |  |  |  |
Futures | $ | 1 |  |  | $ | 1 |  |  | $ | — |  |  | $ | — |
Foreign currency forward payable | 3 |  |  | — |  |  | 3 |  |  | — |
Swaps | 6 |  |  | — |  |  | 6 |  |  | — |
Options | 2 |  |  | — |  |  | 2 |  |  | — |
Securities sold under agreements to repurchase | 123 |  |  | — |  |  | 123 |  |  | — |
Total liabilities | $ | 135 |  |  | $ | 1 |  |  | $ | 134 |  |  | $ | — |
Notes (1) Excludes approximately $107 million in net payables associated with security purchases and sales and various other payables. (2) Excludes a $167 million payable for collateral on loaned securities in connection with TVARS's participation in securities lending programs. (3) In accordance with Subtopic 820-10, certain investments that are measured at fair value using the net asset value per share (or its equivalent) practical expedient have not been classified in the fair value hierarchy. The following table provides the fair value measurement amounts for assets held by TVARS at September 30, 2019:
TVA Retirement System At September 30, 2019
| Total(1)(2) |  | Quoted Prices in Active Markets for Identical Assets/Liabilities (Level 1) |  | Significant Other Observable Inputs (Level 2) |  | Significant Unobservable Inputs (Level 3)
Assets |  |  |  |  |  |  |
Equity securities | $ | 1,766 |  |  | $ | 1,762 |  |  | $ | — |  |  | $ | 4 |
Preferred securities | 10 |  |  | 1 |  |  | 9 |  |  | — |
Debt securities |  |  |  |  |  |  |
Corporate debt securities | 1,387 |  |  | — |  |  | 1,382 |  |  | 5 |
Residential mortgage-backed securities | 427 |  |  | — |  |  | 424 |  |  | 3 |
Debt securities issued by U.S. Treasury | 807 |  |  | 807 |  |  | — |  |  | — |
Debt securities issued by foreign governments | 210 |  |  | — |  |  | 209 |  |  | 1 |
Asset-backed securities | 144 |  |  | — |  |  | 116 |  |  | 28 |
Debt securities issued by state/local governments | 18 |  |  | — |  |  | 18 |  |  | — |
Commercial mortgage-backed securities | 81 |  |  | — |  |  | 80 |  |  | 1 |
Commingled funds measured at net asset value(3) |  |  |  |  |  |  |
Equity | 795 |  |  | — |  |  | — |  |  | — |
Debt | 308 |  |  | — |  |  | — |  |  | — |
Commodities | 217 |  |  | — |  |  | — |  |  | — |
Blended | 125 |  |  | — |  |  | — |  |  | — |
Institutional mutual funds | 97 |  |  | 97 |  |  | — |  |  | — |
Cash equivalents and other short-term investments | 329 |  |  | 1 |  |  | 328 |  |  | — |
Certificates of deposit | 3 |  |  | — |  |  | 3 |  |  | — |
Private credit measured at net asset value(3) | 78 |  |  | — |  |  | — |  |  | — |
Private equity measured at net asset value(3) | 778 |  |  | — |  |  | — |  |  | — |
Private real assets measured at net asset value(3) | 659 |  |  | — |  |  | — |  |  | — |
Securities lending collateral | 224 |  |  | — |  |  | 224 |  |  | — |
Derivatives |  |  |  |  |  |  |
Futures | 2 |  |  | 2 |  |  | — |  |  | — |
Swaps | 5 |  |  | — |  |  | 5 |  |  | — |
Options | 1 |  |  | — |  |  | 1 |  |  | — |
Foreign currency forward receivable | 1 |  |  | — |  |  | 1 |  |  | — |
Total assets | $ | 8,472 |  |  | $ | 2,670 |  |  | $ | 2,800 |  |  | $ | 42 |
Liabilities |  |  |  |  |  |  |
Derivatives |  |  |  |  |  |  |
Futures | $ | 4 |  |  | $ | 4 |  |  | $ | — |  |  | $ | — |
Foreign currency forward payable | 1 |  |  | — |  |  | 1 |  |  | — |
Swaps | 12 |  |  | — |  |  | 12 |  |  | — |
Options | 1 |  |  | — |  |  | 1 |  |  | — |
Securities sold under agreements to repurchase | 118 |  |  | — |  |  | 118 |  |  | — |
Total liabilities | $ | 136 |  |  | $ | 4 |  |  | $ | 132 |  |  | $ | — |
cNotes (1) Excludes approximately $132 million in net payables associated with security purchases and sales and various other payables. (2) Excludes a $224 million payable for collateral on loaned securities in connection with TVARS's participation in securities lending programs.
Fair Value Measurements Using Significant Unobservable Inputs | The following table provides a reconciliation of beginning and ending balances of pension plan assets measured at fair value on a recurring basis where the determination of fair value includes significant unobservable inputs (Level 3):
Fair Value Measurements Using Significant Unobservable Inputs
| Fair Value Measurements Using Significant Unobservable Inputs (Level 3)
Balance at October 1, 2018 | $ | 58 |
Net realized/unrealized gains (losses) | 4 |
Purchases, sales, issuances, and settlements (net) | (12) |
Transfers in and/or out of Level 3 | (8) |
Balance at September 30, 2019 | 42 |
Net realized/unrealized gains (losses) | 46 |
Purchases, sales, issuances, and settlements (net) | 11 |
Transfers in and/or out of Level 3 | (5) |
Balance at September 30, 2020 | $ | 94 |
Estimated Future Benefit Payments | Cash Flows Estimated Future Benefit Payments. The following table sets forth the estimated future benefit payments under the benefit plans.
Estimated Future Benefits Payments At September 30, 2020
| Pension Benefits(1) |  | Other Post-Retirement Benefits
2021 | $ | 777 |  |  | $ | 28 |
2022 | 776 |  |  | 26 |
2023 | 773 |  |  | 24 |
2024 | 768 |  |  | 23 |
2025 | 767 |  |  | 22 |
2026 - 2030 | 3,741 |  |  | 117 |
Note (1) Participants are assumed to receive the Fixed Fund in a lump sum in lieu of available annuity options allowed for certain grandfathered participants resulting in higher estimated pension benefits payments.
Amounts recognized on Consolidated Balance Sheets |
Amounts Recognized on TVA's Consolidated Balance Sheets At September 30
| 2020 |  | 2019
Accounts payable and accrued liabilities | $ | — |  |  | $ | 36 |
Post-retirement and post-employment benefit obligations | 390 |  |  | 383 |

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