Summary of Significant Accounting Policies and Other Matters (Policies)	12 Months Ended
Dec. 31, 2022
Accounting Policies [Abstract]
Principles of Consolidation	Principles of Consolidation The Companies’ consolidated financial statements include the accounts of their respective majority-owned subsidiaries, and variable interest entities (see Note S), as required. All intercompany balances and intercompany transactions have been eliminated.
Accounting Policies	Accounting Policies The accounting policies of Con Edison and its subsidiaries conform to generally accepted accounting principles in the United States of America (GAAP). For the Utilities, these accounting principles include the accounting rules for regulated operations and the accounting requirements of the Federal Energy Regulatory Commission (FERC) and the state regulators having jurisdiction. The accounting rules for regulated operations specify the economic effects that result from the causal relationship of costs and revenues in the rate-regulated environment and how these effects are to be accounted for by a regulated enterprise. Revenues intended to cover some costs may be recorded either before or after the costs are incurred. If regulation provides assurance that incurred costs will be recovered in the future, these costs would be recorded as deferred charges or “regulatory assets” under the accounting rules for regulated operations. If revenues are recorded for costs that are expected to be incurred in the future, these revenues would be recorded as deferred credits or “regulatory liabilities” under the accounting rules for regulated operations. The Utilities’ principal regulatory assets and liabilities are detailed in Note B. In general, the Utilities are receiving or being credited with a return on their regulatory assets for which a cash outflow has been made, and are paying or being charged with a return on their regulatory liabilities for which a cash inflow has been received. The Utilities’ regulatory assets and liabilities at December 31, 2022 are recoverable from customers, or to be applied for customer benefit, in accordance with rate provisions that have been approved by state regulators.
Revenues	Revenues CECONY’s electric and gas rate plans and O&R’s NY electric and gas rate plans each contain a revenue decoupling mechanism, that covers all residential and most commercial customers, under which the company’s actual energy delivery revenues are compared with the authorized delivery revenues and the difference accrued, with interest, for refund to, or recovery from, customers, as applicable. See “Rate Plans” in Note B. The NYSPSC requires utilities to record gross receipts tax revenues and expenses on a gross income statement presentation basis (i.e., included in both revenue and expense). The recovery of these taxes is generally provided for in the revenue requirement within each of the respective NYSPSC-approved rate plans.
Plant and Depreciation Utility Plant / Non-Utility Plant	Plant and Depreciation Utility Plant Utility plant is stated at original cost. The cost of repairs and maintenance is charged to expense and the cost of betterments is capitalized. The capitalized cost of additions to utility plant includes indirect costs such as engineering, supervision, payroll taxes, pensions, other benefits and an allowance for funds used during construction (AFUDC). The original cost of property is charged to expense over the estimated useful lives of the assets. Upon retirement, the original cost of property is charged to accumulated depreciation. See- Note T. Rates used for AFUDC include the cost of borrowed funds and a reasonable rate of return on the Utilities’ own funds when so used, determined in accordance with regulations of the FERC or the state public utility regulatory authority having jurisdiction. The rate is compounded semiannually, and the amounts applicable to borrowed funds are treated as a reduction of interest charges, while the amounts applicable to the Utilities’ own funds are credited to other income (deductions). The AFUDC rates for CECONY were 5.2 percent, 4.5 percent and 5.2 percent for 2022, 2021 and 2020, respectively. The AFUDC rates for O&R were 5.0 percent, 4.8 percent and 5.3 percent for 2022, 2021 and 2020, respectively. The Utilities generally compute annual charges for depreciation using the straight-line method for financial statement purposes, with rates based on average service lives and net salvage factors. The average depreciation rates for CECONY were 3.5 percent for 2022 and 3.5 percent for 2021 and 3.5 percent for 2020. The average depreciation rates for O&R were 3.0 percent for 2022, 3.1 percent for 2021 and 3.2 percent for 2020. The estimated lives for utility plant for CECONY range from 5 to 80 years for electric, 5 to 90 years for gas, 5 to 80 years for steam and 5 to 55 years for general plant. For O&R, the estimated lives for utility plant range from 5 to 75 years for electric and gas and 5 to 50 years for general plant. Non–Utility Plant Non-utility plant is stated at original cost. For Con Edison, non-utility plant consists primarily of the Clean Energy Businesses’ renewable electric projects. Property, plant and equipment are stated at cost, less accumulated depreciation and include capitalized interest during construction. Depreciation is computed under the straight-line method over the useful lives of the assets. Solar power generating assets and wind power generating assets have useful lives of 35 years and 30, respectively. The Clean Energy Businesses were classified as held for sale as of December 31, 2022, and depreciation on their assets was not recorded for the three months ended December 31, 2022. See "Assets and Liabilities Held for Sale" below, and Note X. For the Utilities, non-utility plant consists of land and conduit for telecommunication use. Depreciation on non-utility plant, other than land, is computed using the straight-line method for financial statement purposes over their estimated useful lives, which is 10 years.
Long-Lived and Intangible Assets	Long–Lived and Intangible Assets The Companies test long-lived and intangible assets for recoverability when events or changes in circumstances indicate that the carrying value of long-lived or intangible assets may not be recoverable. The carrying amount of a long-lived asset or intangible asset with a definite life is deemed not recoverable if it exceeds the sum of the undiscounted cash flows expected to result from the use and eventual disposition of the assets. In the event a test indicates that such cash flows cannot be expected to be sufficient to fully recover the assets, the assets are considered impaired and written down to their estimated fair value.
Recoverable Energy Costs/New York Independent System Operator (NYISO)	Recoverable Energy Costs The Utilities generally recover all of their prudently incurred fuel, purchased power and gas costs, including hedging gains and losses, in accordance with rate provisions approved by the applicable state public utility regulators. If the actual energy supply costs for a given month are more or less than the amounts billed to customers for that month, the difference in most cases is recoverable from or refundable to customers. Differences between actual and billed electric and steam supply costs are generally deferred for charge or refund to customers during the next billing cycle (normally within one or two months). For the Utilities’ gas costs, differences between actual and billed gas costs during the 12-month period ending each August are charged or refunded to customers during a subsequent 12-month period. New York Independent System Operator (NYISO) The Utilities purchase electricity through the wholesale electricity market administered by the NYISO. The difference between purchased power and related costs initially billed to the Utilities by the NYISO and the actual cost of power subsequently calculated by the NYISO is refunded by the NYISO to the Utilities, or paid to the NYISO by the Utilities. The reconciliation payments or receipts are recoverable from or refundable to the Utilities’ customers. Certain other payments to or receipts from the NYISO are also subject to reconciliation, with shortfalls or amounts in excess of specified rate allowances recoverable from or refundable to customers. These include proceeds from the sale through the NYISO of transmission rights on CECONY’s transmission system (transmission congestion contracts or TCCs).
Temporary Cash Investments	Temporary Cash Investments Temporary cash investments are short-term, highly-liquid investments that generally have maturities of three months or less at the date of purchase. They are stated at cost, which approximates market. The Companies consider temporary cash investments to be cash equivalents.
Investments	Investments Accounting for Investments Con Edison’s investments consist primarily of the investments of Con Edison Transmission that are accounted for under the equity method and the fair value of the Utilities’ supplemental retirement income plan and deferred income plan assets. The accounting rules require Con Edison to evaluate its investments periodically to determine whether they are impaired. The standard for determining whether an impairment exists and must be recorded is whether an other-than-temporary decline in carrying value has occurred. Changes in economic conditions, forecasted cash flows and the regulatory environment, among other factors, could require equity method investments to recognize a decrease in carrying value for an other-than-temporary decline. When management believes such a decline may have occurred, the fair value of the investment is estimated using market inputs, when observable, or a market valuation model such as a discounted cash flow analysis. The fair value is compared to the carrying value of the investment in order to determine the amount of impairment to record, if any. The evaluation and measurement of impairments involve uncertainties. The judgments that Con Edison makes to estimate the fair value of its equity method investments are based on assumptions that management believes are reasonable, and variations in these estimates or the underlying assumptions, or the receipt of additional market information, could have a material impact on whether a triggering event is determined to exist or the amount of any such impairment. Additionally, if the projects in which Con Edison holds these investments recognize an impairment, Con Edison may record a share of that impairment loss and would evaluate its investment for an other-than-temporary decline in carrying value as described above. 2021 Partial Impairment of Investment in Stagecoach Gas Services LLC (Stagecoach) In May 2021, a subsidiary of Con Edison Gas Pipeline and Storage, LLC (CET) entered into a purchase and sale agreement pursuant to which the subsidiary and its joint venture partner agreed to sell their combined interests in Stagecoach Gas Services LLC (Stagecoach) for a total of $1,225 million, of which $629 million was attributed to CET for its 50 percent interest. The purchase and sale agreement contemplated a two-stage closing, the first of which was completed in July 2021 and the second of which was completed in November 2021. As a result of information made available to Stagecoach as part of the sale process, Stagecoach performed impairment tests that resulted in Stagecoach recording impairment charges of $414 million for the year ended December 31, 2021. Accordingly, Con Edison recorded pre-tax impairment losses on its 50 percent interest in Stagecoach of $212 million ($147 million after-tax), including working capital and transaction cost adjustments, within "Investment income/(loss)" on Con Edison's consolidated income statement for the year ended December 31, 2021. Stagecoach’s impairment charges and information obtained from the sales process constituted triggering events for Con Edison's investment in Stagecoach as of March 31, 2021 and June 30, 2021. Con Edison evaluated the carrying value of its investment in Stagecoach for other-than-temporary declines in value using income and market-based approaches. Con Edison determined that the carrying value of its investment in Stagecoach of $667 million and $630 million as of March 31, 2021 and June 30, 2021, respectively, was not impaired. The carrying value of $630 million at June 30, 2021 reflected the final sales price received in July and the remaining amount received in November 2021, including closing adjustments. CET had no remaining investment in Stagecoach as of December 31, 2021 and 2022. 2020 and 2021 Partial Impairments of Investment in Mountain Valley Pipeline, LLC (MVP) In January 2016, Con Edison Gas Pipeline and Storage, LLC (CET), an indirect subsidiary of Con Edison, acquired a 12.5 percent equity interest in MVP, a company developing a proposed 300-mile gas transmission project (the Project) in WV and VA. During 2019, Con Edison exercised its right to limit, and did limit, its cash contributions to the joint venture to approximately $530 million, which reduced CET's interest in MVP to 11.3 percent and 10.2 percent as of December 31, 2020 and 2021, respectively. As of December 31, 2022 CET's interest in MVP is 9.6 percent and is expected to be reduced to 8.0 percent based on the Project's current cost estimate and CET's previous capping of its cash contributions. As of December 31, 2021 and 2022, the Project was approximately 94 percent complete. During 2020, progress was made on the construction of the Project, and the U.S. Supreme Court issued favorable decisions in cases unrelated to MVP regarding the permitting process for pipeline construction and water crossings. In November 2020, the U.S. Court of Appeals for the Fourth Circuit issued a stay on the Nationwide Permit 12, effectively blocking the Project’s ability to pursue water crossings under that permit. As a result, in November 2020 the Project applied to the FERC for a certificate amendment to bore under water bodies in a portion of the Project in WV, allowing this portion of the pipe to be completed and placed in-service while a plan for the remaining water crossings was pursued. If approved, this certificate amendment would have led to additional Project costs and would have extended the anticipated in-service date. In January 2021, the FERC did not approve the requested certificate amendment. Later in January 2021, the Project indicated its plans to apply for U.S. Army Corps of Engineers individual permits for certain water crossings and a new certificate amendment application to the FERC to bore under other water crossings that, in total, would cover the entire Project length. The uncertainty related to obtaining necessary water crossing permits, the resulting Project costs and the likelihood of the Project not reaching eventual completion increased as a result of actions taken by the U.S. Court of Appeals for the Fourth Circuit. This action and associated delays constituted a triggering event (the "2020 triggering event") that required Con Edison to test its investment in MVP for an other-than-temporary impairment as of December 31, 2020. In December 2021, the VA Department of Environmental Quality and the WV Department of Environmental Protection both issued water quality certification permits which are required in order for the U.S. Army Corps of Engineers to proceed with the permitting process for construction of certain Project water crossings. In January 2022, the U.S. Court of Appeals for the Fourth Circuit rejected permits for crossings through the Jefferson National Forest issued by the U.S. Forest Service and Bureau of Land Management. In February 2022, the U.S. Court of Appeals for the Fourth Circuit vacated a biological opinion from the U.S. Fish and Wildlife Service, applicable to all remaining construction. The biological opinion had been issued and was the subject of litigation prior to December 31, 2021. Con Edison believed that the February 2022 action by the U.S. Court of Appeals for the Fourth Circuit, along with the potential outcome of other matters pending before that Court, may lead to further delays and increased Project costs, which constituted a triggering event (the “2021 triggering event”) that required Con Edison to test its investment in MVP for an other-than-temporary impairment as of December 31, 2021. In response to the 2020 triggering event and 2021 triggering event, Con Edison assessed the value of its equity investment in the Project to determine whether the fair value of its investment in MVP had declined below its carrying value on an other-than-temporary basis as of December 31, 2020 and 2021, respectively. The estimated fair value of the investment was determined using a discounted cash flow analysis, which is a level 3 fair value measurement. The analysis discounted probability-weighted future cash flows, including revenues based on long-term firm transportation contracts, that are secured for the first 20 years following completion of the Project. See Note U. Con Edison has also assumed cash flows extending beyond this period. All cash flows were discounted at a pre-tax discount rate of 8.3 percent and then weighted based on Con Edison’s estimate of the likelihood that the Project will be completed. For the 2020 triggering event, Con Edison estimated that the likelihood of Project completion was in the upper end of a reasonably possible range. For the 2021 triggering event, Con Edison anticipated that the Project faces legal and regulatory challenges that make construction completion increasingly remote. The Project faces additional delays and increased costs that could further reduce CET's interest in MVP to below 8 percent based on CET's previous capping of its cash contributions. The likelihood that the Project will be completed and, for 2020, the discount rate, are the most significant and sensitive assumptions; changes in these assumptions may materially change the results of the impairment calculation. Based on the discounted cash flow analyses, Con Edison concluded as of December 31, 2020 and 2021 that the fair value of its investment in MVP declined below its carrying value and the declines were other-than-temporary. Accordingly, Con Edison recorded a pre-tax impairment loss of $320 million ($223 million, after tax) for the year ended December 31, 2020 that reduced the carrying value of its investment in MVP from $662 million to $342 million, with an associated deferred tax asset of $53 million. Additionally, Con Edison recorded a pre-tax impairment loss of $231 million ($162 million, after tax) for the year ended December 31, 2021 that reduced the carrying value of its investment in MVP from $342 million to $111 million, with an additional $77 million associated deferred tax asset, totaling a deferred tax asset of $130 million at December 31, 2021 and 2022. The impairments were recorded within “Investment income (loss)” on Con Edison’s Consolidated Income Statement. In addition, Con Edison did not record non-cash equity in earnings from allowance for funds used during construction from MVP beginning in January 2021 and will continue to refrain from recording such amounts until such time as substantial construction activities resume, which would be indicative of probable Project completion. There were no impairments or substantial changes in the carrying value of Con Edison's investment in MVP for the year ended December 31, 2022. There is risk that the fair value of Con Edison’s investment in MVP may be further or fully impaired in the future. There are ongoing legal and regulatory matters that must be resolved favorably before the Project can be completed. Assumptions and estimates used to test Con Edison’s investment in MVP for impairment may change if adverse or delayed resolutions to the Project’s pending legal and regulatory challenges were to occur, which could have a material adverse effect on the fair value of Con Edison’s investment in MVP.
Pension and Other Postretirement Benefits	Pension and Other Postretirement Benefits The accounting rules for retirement benefits require an employer to recognize an asset or liability for the overfunded or underfunded status of its pension and other postretirement benefit plans. For a pension plan, the asset or liability is the difference between the fair value of the plan’s assets and the projected benefit obligation. For any other postretirement benefit plan, the asset or liability is the difference between the fair value of the plan’s assets and the accumulated postretirement benefit obligation. The accounting rules generally require employers to recognize all unrecognized prior service costs and credits and unrecognized actuarial gains and losses in accumulated other comprehensive income/(loss) (OCI), net of tax. Such amounts will be adjusted as they are subsequently recognized as components of total periodic benefit cost or income pursuant to the current recognition and amortization provisions. For the Utilities’ pension and other postretirement benefit plans, regulatory accounting treatment is generally applied in accordance with the accounting rules for regulated operations. Unrecognized prior service costs or credits and unrecognized actuarial gains and losses are recorded to regulatory assets or liabilities, rather than OCI. See Notes E and F. The total periodic benefit costs are recognized in accordance with the accounting rules for retirement benefits. Investment gains and losses are recognized in expense over a 15-year period and other actuarial gains and losses are recognized in expense over a 10-year period, subject to the deferral provisions in the rate plans. In accordance with the Statement of Policy issued by the NYSPSC and its current electric, gas and steam rate plans, CECONY defers for payment to or recovery from customers the difference between such expenses and the amounts for such expenses reflected in rates. O&R also defers such difference pursuant to its NY rate plans. See Note B. The Companies calculate the expected return on pension and other postretirement benefit plan assets by multiplying the expected rate of return on plan assets by the market-related value (MRV) of plan assets at the beginning of the year, taking into consideration anticipated contributions and benefit payments that are to be made during the year. The accounting rules allow the MRV of plan assets to be either fair value or a calculated value that recognizes changes in fair value in a systematic and rational manner over not more than five years. The Companies use a calculated value when determining the MRV of the plan assets that adjusts for 20 percent of the difference between fair value and expected MRV of plan assets. This calculated value has the effect of stabilizing variability in assets to which the Companies apply the expected return.
Federal Income Tax/State Income Tax	Federal Income Tax In accordance with accounting rules for income taxes, the Companies have recorded an accumulated deferred federal income tax liability at current tax rates for temporary differences between the book and tax basis of assets and liabilities. In accordance with rate plans, the Utilities have recovered amounts from customers for a portion of the tax liability they will pay in the future as a result of the reversal or “turn-around” of these temporary differences. As to the remaining deferred tax liability, the Utilities had established regulatory assets for the net revenue requirements to be recovered from customers for the related future tax expense pursuant to the NYSPSC's 1993 Policy Statement approving accounting procedures consistent with accounting rules for income taxes and providing assurances that these future increases in taxes will be recoverable in rates. Accumulated deferred investment tax credits are amortized ratably over the lives of the related properties and applied as a reduction to future federal income tax expense. Con Edison and its subsidiaries file a consolidated federal income tax return. The consolidated income tax liability is allocated to each member of the consolidated group using the separate return method. Each member pays or receives an amount based on its own taxable income or loss in accordance with a consolidated tax allocation agreement. Tax loss and tax credit carryforwards are allocated among members in accordance with consolidated tax return regulations. State Income Tax Con Edison and its subsidiaries file a combined New York State Corporation Business Franchise Tax Return. Similar to a federal consolidated income tax return, the income of all entities in the combined group is subject to New York State taxation, after adjustments for differences between federal and New York law and apportionment of income among the states in which the company does business. Each member’s share of the New York State tax is based on its own New York State taxable income or loss.
Research and Development Costs	Research and Development CostsResearch and development costs are charged to operating expenses as incurred.
Reclassification	Reclassification Certain prior period amounts have been reclassified within the Companies' Consolidated Statements of Cash Flows and Consolidated Balance Sheets to conform with current period presentation.
Earnings Per Common Share	Earnings Per Common Share Con Edison presents basic and diluted earnings per share (EPS) on the face of its consolidated income statement. Basic EPS is calculated by dividing earnings available to common shareholders (“Net income for common stock” on Con Edison’s consolidated income statement) by the weighted average number of Con Edison common shares outstanding during the period. In the calculation of diluted EPS, weighted average shares outstanding are increased for additional shares that would be outstanding if potentially dilutive securities were converted to common stock. Potentially dilutive securities for Con Edison consist of restricted stock units and deferred stock units for which the average market price of the common shares for the period was greater than the exercise price (see Note O) and its common shares that are subject to forward sale agreements (see Note C). Before the issuance of common shares upon settlement of the forward sale agreements, the shares will be reflected in the company’s diluted earnings per share calculations using the treasury stock method. Under this method, the number of common shares used in calculating diluted earnings per share is deemed to be increased by the excess, if any, of the number of shares that would be issued upon physical settlement of the forward sale agreements over the number of shares that could be purchased by the company in the market (based on the average market price during the period) using the proceeds due upon physical settlement (based on the adjusted forward sale price at the end of the reporting period).
Estimates	Estimates The preparation of financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and contingent assets and liabilities at the date of the financial statements and the reported amounts of revenues and expenses during the reporting period. Actual results could differ from those estimates.
New Financial Accounting Standards	New Financial Accounting Standards In March 2020, the FASB issued ASU 2020-04, Reference Rate Reform (Topic 848): Facilitation of the Effects of Reference Rate Reform on Financial Reporting (ASU 2020-04). In 2017, the United Kingdom’s Financial Conduct Authority announced that it intends to stop persuading or compelling banks to submit the London Interbank Offered Rate (LIBOR), a benchmark interest rate referenced in a variety of agreements, after 2021. The United Kingdom's Financial Conduct Authority ceased publication of U.S. Dollar LIBOR after December 31, 2021 for one-week and two-month U.S. Dollar LIBOR tenors, and expects to cease publishing after June 30, 2023 for all other U.S. Dollar LIBOR tenors. ASU 2020-04 provides entities with optional expedients and exceptions for applying generally accepted accounting principles to contract modifications and hedging relationships, subject to meeting certain criteria, that reference LIBOR or another reference rate expected to be discontinued. In January 2021, the FASB issued amendments to the guidance through ASU 2021-01 to include all contract modifications and hedging relationships affected by reference rate reform, including those that do not directly reference LIBOR or another reference rate expected to be discontinued, and clarify which optional expedients may be applied to them. As the Companies continue to modify contracts that contain references to LIBOR that allow for the use of an alternative rate, they have applied the practical expedient to not assess each change for a contract modification. The guidance can be applied prospectively. The optional relief is temporary and generally cannot be applied to contract modifications and hedging relationships entered into or evaluated after December 31, 2024, which date reflects the updates in ASU 2022-06, Reference Rate Reform (Topic 848): Deferral of the Sunset Date of Topic 848. The Companies do not expect the guidance to have a material impact on their financial position, results of operations or liquidity. In December 2021, the FASB issued amendments to the guidance on accounting for government assistance through ASU 2021-10, Government Assistance (Topic 832): Disclosures by Business Entities about Government Assistance. The amendments require that business entities that apply a grant or contribution model by analogy to other accounting guidance disclose 1) the types of assistance, 2) an entity’s accounting for the assistance, and 3) the effect of the assistance on an entity’s financial statements. For public entities, the amendments are effective for reporting periods beginning after December 15, 2021. Early adoption is permitted. The Companies have concluded the new guidance does not have a material impact on the Companies’ financial position, results of operations and liquidity.

Summary of Significant Accounting Policies and Other Matters (Policies)

12 Months Ended

Dec. 31, 2022

The Companies’ consolidated financial statements include the accounts of their respective majority-owned subsidiaries, and variable interest entities (see Note S), as required. All intercompany balances and intercompany transactions have been eliminated.

Accounting Policies

The accounting policies of Con Edison and its subsidiaries conform to generally accepted accounting principles in the United States of America (GAAP). For the Utilities, these accounting principles include the accounting rules for regulated operations and the accounting requirements of the Federal Energy Regulatory Commission (FERC) and the state regulators having jurisdiction.

The accounting rules for regulated operations specify the economic effects that result from the causal relationship of costs and revenues in the rate-regulated environment and how these effects are to be accounted for by a regulated enterprise. Revenues intended to cover some costs may be recorded either before or after the costs are incurred. If regulation provides assurance that incurred costs will be recovered in the future, these costs would be recorded as deferred charges or “regulatory assets” under the accounting rules for regulated operations. If revenues are recorded for costs that are expected to be incurred in the future, these revenues would be recorded as deferred credits or “regulatory liabilities” under the accounting rules for regulated operations.

The Utilities’ principal regulatory assets and liabilities are detailed in Note B. In general, the Utilities are receiving or being credited with a return on their regulatory assets for which a cash outflow has been made, and are paying or being charged with a return on their regulatory liabilities for which a cash inflow has been received. The Utilities’ regulatory assets and liabilities at December 31, 2022 are recoverable from customers, or to be applied for customer benefit, in accordance with rate provisions that have been approved by state regulators.

Revenues

CECONY’s electric and gas rate plans and O&R’s NY electric and gas rate plans each contain a revenue decoupling mechanism, that covers all residential and most commercial customers, under which the company’s actual energy delivery revenues are compared with the authorized delivery revenues and the difference accrued, with interest, for refund to, or recovery from, customers, as applicable. See “Rate Plans” in Note B.

The NYSPSC requires utilities to record gross receipts tax revenues and expenses on a gross income statement presentation basis (i.e., included in both revenue and expense). The recovery of these taxes is generally provided for in the revenue requirement within each of the respective NYSPSC-approved rate plans.

Plant and Depreciation Utility Plant / Non-Utility Plant

Plant and Depreciation

Utility Plant

Utility plant is stated at original cost. The cost of repairs and maintenance is charged to expense and the cost of betterments is capitalized. The capitalized cost of additions to utility plant includes indirect costs such as engineering, supervision, payroll taxes, pensions, other benefits and an allowance for funds used during construction (AFUDC). The original cost of property is charged to expense over the estimated useful lives of the assets. Upon retirement, the original cost of property is charged to accumulated depreciation. See- Note T.

Rates used for AFUDC include the cost of borrowed funds and a reasonable rate of return on the Utilities’ own funds when so used, determined in accordance with regulations of the FERC or the state public utility regulatory authority

having jurisdiction. The rate is compounded semiannually, and the amounts applicable to borrowed funds are treated as a reduction of interest charges, while the amounts applicable to the Utilities’ own funds are credited to other income (deductions). The AFUDC rates for CECONY were 5.2 percent, 4.5 percent and 5.2 percent for 2022, 2021 and 2020, respectively. The AFUDC rates for O&R were 5.0 percent, 4.8 percent and 5.3 percent for 2022, 2021 and 2020, respectively.

The Utilities generally compute annual charges for depreciation using the straight-line method for financial statement purposes, with rates based on average service lives and net salvage factors. The average depreciation rates for CECONY were 3.5 percent for 2022 and 3.5 percent for 2021 and 3.5 percent for 2020. The average depreciation rates for O&R were 3.0 percent for 2022, 3.1 percent for 2021 and 3.2 percent for 2020.

The estimated lives for utility plant for CECONY range from 5 to 80 years for electric, 5 to 90 years for gas, 5 to 80 years for steam and 5 to 55 years for general plant. For O&R, the estimated lives for utility plant range from 5 to 75 years for electric and gas and 5 to 50 years for general plant.

Non–Utility Plant

Non-utility plant is stated at original cost. For Con Edison, non-utility plant consists primarily of the Clean Energy Businesses’ renewable electric projects. Property, plant and equipment are stated at cost, less accumulated depreciation and include capitalized interest during construction. Depreciation is computed under the straight-line method over the useful lives of the assets. Solar power generating assets and wind power generating assets have useful lives of 35 years and 30, respectively. The Clean Energy Businesses were classified as held for sale as of December 31, 2022, and depreciation on their assets was not recorded for the three months ended December 31, 2022. See "Assets and Liabilities Held for Sale" below, and Note X.

For the Utilities, non-utility plant consists of land and conduit for telecommunication use. Depreciation on non-utility plant, other than land, is computed using the straight-line method for financial statement purposes over their estimated useful lives, which is 10 years.

Long-Lived and Intangible Assets

Long–Lived and Intangible Assets

The Companies test long-lived and intangible assets for recoverability when events or changes in circumstances indicate that the carrying value of long-lived or intangible assets may not be recoverable. The carrying amount of a long-lived asset or intangible asset with a definite life is deemed not recoverable if it exceeds the sum of the undiscounted cash flows expected to result from the use and eventual disposition of the assets. In the event a test indicates that such cash flows cannot be expected to be sufficient to fully recover the assets, the assets are considered impaired and written down to their estimated fair value.

Recoverable Energy Costs/New York Independent System Operator (NYISO)

Recoverable Energy Costs

The Utilities generally recover all of their prudently incurred fuel, purchased power and gas costs, including hedging gains and losses, in accordance with rate provisions approved by the applicable state public utility regulators. If the actual energy supply costs for a given month are more or less than the amounts billed to customers for that month, the difference in most cases is recoverable from or refundable to customers. Differences between actual and billed electric and steam supply costs are generally deferred for charge or refund to customers during the next billing cycle (normally within one or two months). For the Utilities’ gas costs, differences between actual and billed gas costs during the 12-month period ending each August are charged or refunded to customers during a subsequent 12-month period.

New York Independent System Operator (NYISO)

The Utilities purchase electricity through the wholesale electricity market administered by the NYISO. The difference between purchased power and related costs initially billed to the Utilities by the NYISO and the actual cost of power subsequently calculated by the NYISO is refunded by the NYISO to the Utilities, or paid to the NYISO by the Utilities. The reconciliation payments or receipts are recoverable from or refundable to the Utilities’ customers.

Certain other payments to or receipts from the NYISO are also subject to reconciliation, with shortfalls or amounts in excess of specified rate allowances recoverable from or refundable to customers. These include proceeds from the sale through the NYISO of transmission rights on CECONY’s transmission system (transmission congestion contracts or TCCs).

Temporary Cash Investments

Temporary cash investments are short-term, highly-liquid investments that generally have maturities of three months or less at the date of purchase. They are stated at cost, which approximates market. The Companies consider temporary cash investments to be cash equivalents.

Investments

Accounting for Investments

Con Edison’s investments consist primarily of the investments of Con Edison Transmission that are accounted for under the equity method and the fair value of the Utilities’ supplemental retirement income plan and deferred income plan assets.

The accounting rules require Con Edison to evaluate its investments periodically to determine whether they are impaired. The standard for determining whether an impairment exists and must be recorded is whether an other-than-temporary decline in carrying value has occurred. Changes in economic conditions, forecasted cash flows and the regulatory environment, among other factors, could require equity method investments to recognize a decrease in carrying value for an other-than-temporary decline. When management believes such a decline may have occurred, the fair value of the investment is estimated using market inputs, when observable, or a market valuation model such as a discounted cash flow analysis. The fair value is compared to the carrying value of the investment in order to determine the amount of impairment to record, if any.

The evaluation and measurement of impairments involve uncertainties. The judgments that Con Edison makes to estimate the fair value of its equity method investments are based on assumptions that management believes are reasonable, and variations in these estimates or the underlying assumptions, or the receipt of additional market information, could have a material impact on whether a triggering event is determined to exist or the amount of any such impairment. Additionally, if the projects in which Con Edison holds these investments recognize an impairment, Con Edison may record a share of that impairment loss and would evaluate its investment for an other-than-temporary decline in carrying value as described above.

2021 Partial Impairment of Investment in Stagecoach Gas Services LLC (Stagecoach)

In May 2021, a subsidiary of Con Edison Gas Pipeline and Storage, LLC (CET) entered into a purchase and

sale agreement pursuant to which the subsidiary and its joint venture partner agreed to sell their combined interests

in Stagecoach Gas Services LLC (Stagecoach) for a total of $1,225 million, of which $629 million was attributed to

CET for its 50 percent interest. The purchase and sale agreement contemplated a two-stage closing, the first of

which was completed in July 2021 and the second of which was completed in November 2021.

As a result of information made available to Stagecoach as part of the sale process, Stagecoach performed impairment tests that resulted in Stagecoach recording impairment charges of $414 million for the year ended December 31, 2021. Accordingly, Con Edison recorded pre-tax impairment losses on its 50 percent interest in Stagecoach of $212 million ($147 million after-tax), including working capital and transaction cost adjustments, within "Investment income/(loss)" on Con Edison's consolidated income statement for the year ended December 31, 2021.

Stagecoach’s impairment charges and information obtained from the sales process constituted triggering events for Con Edison's investment in Stagecoach as of March 31, 2021 and June 30, 2021. Con Edison evaluated the carrying value of its investment in Stagecoach for other-than-temporary declines in value using income and market-based approaches. Con Edison determined that the carrying value of its investment in Stagecoach of $667 million and $630 million as of March 31, 2021 and June 30, 2021, respectively, was not impaired. The carrying value of $630 million at June 30, 2021 reflected the final sales price received in July and the remaining amount received in November 2021, including closing adjustments. CET had no remaining investment in Stagecoach as of

December 31, 2021 and 2022.

2020 and 2021 Partial Impairments of Investment in Mountain Valley Pipeline, LLC (MVP)

In January 2016, Con Edison Gas Pipeline and Storage, LLC (CET), an indirect subsidiary of Con Edison, acquired a 12.5 percent equity interest in MVP, a company developing a proposed 300-mile gas transmission project (the Project) in WV and VA. During 2019, Con Edison exercised its right to limit, and did limit, its cash contributions to the joint venture to approximately $530 million, which reduced CET's interest in MVP to 11.3 percent and 10.2 percent as of December 31, 2020 and 2021, respectively. As of December 31, 2022 CET's interest in MVP is 9.6 percent and is expected to be reduced to 8.0 percent based on the Project's current cost estimate and CET's previous capping of its cash contributions. As of December 31, 2021 and 2022, the Project was approximately 94 percent complete.

During 2020, progress was made on the construction of the Project, and the U.S. Supreme Court issued favorable decisions in cases unrelated to MVP regarding the permitting process for pipeline construction and water crossings. In November 2020, the U.S. Court of Appeals for the Fourth Circuit issued a stay on the Nationwide Permit 12, effectively blocking the Project’s ability to pursue water crossings under that permit. As a result, in November 2020 the Project applied to the FERC for a certificate amendment to bore under water bodies in a portion of the Project in WV, allowing this portion of the pipe to be completed and placed in-service while a plan for the remaining water crossings was pursued. If approved, this certificate amendment would have led to additional Project costs and would have extended the anticipated in-service date. In January 2021, the FERC did not approve the requested certificate amendment. Later in January 2021, the Project indicated its plans to apply for U.S. Army Corps of Engineers individual permits for certain water crossings and a new certificate amendment application to the FERC to bore under other water crossings that, in total, would cover the entire Project length.

The uncertainty related to obtaining necessary water crossing permits, the resulting Project costs and the likelihood of the Project not reaching eventual completion increased as a result of actions taken by the U.S. Court of Appeals for the Fourth Circuit. This action and associated delays constituted a triggering event (the "2020 triggering event") that required Con Edison to test its investment in MVP for an other-than-temporary impairment as of December 31, 2020.

In December 2021, the VA Department of Environmental Quality and the WV Department of Environmental Protection both issued water quality certification permits which are required in order for the U.S. Army Corps of Engineers to proceed with the permitting process for construction of certain Project water crossings. In January 2022, the U.S. Court of Appeals for the Fourth Circuit rejected permits for crossings through the Jefferson National Forest issued by the U.S. Forest Service and Bureau of Land Management. In February 2022, the U.S. Court of Appeals for the Fourth Circuit vacated a biological opinion from the U.S. Fish and Wildlife Service, applicable to all remaining construction. The biological opinion had been issued and was the subject of litigation prior to December 31, 2021. Con Edison believed that the February 2022 action by the U.S. Court of Appeals for the Fourth Circuit, along with the potential outcome of other matters pending before that Court, may lead to further delays and increased Project costs, which constituted a triggering event (the “2021 triggering event”) that required Con Edison to test its investment in MVP for an other-than-temporary impairment as of December 31, 2021.

In response to the 2020 triggering event and 2021 triggering event, Con Edison assessed the value of its equity investment in the Project to determine whether the fair value of its investment in MVP had declined below its carrying value on an other-than-temporary basis as of December 31, 2020 and 2021, respectively. The estimated fair value of the investment was determined using a discounted cash flow analysis, which is a level 3 fair value measurement. The analysis discounted probability-weighted future cash flows, including revenues based on long-term firm transportation contracts, that are secured for the first 20 years following completion of the Project. See Note U. Con Edison has also assumed cash flows extending beyond this period. All cash flows were discounted at a pre-tax discount rate of 8.3 percent and then weighted based on Con Edison’s estimate of the likelihood that the Project will be completed. For the 2020 triggering event, Con Edison estimated that the likelihood of Project completion was in the upper end of a reasonably possible range. For the 2021 triggering event, Con Edison anticipated that the Project faces legal and regulatory challenges that make construction completion increasingly remote. The Project faces additional delays and increased costs that could further reduce CET's interest in MVP to below 8 percent based on CET's previous capping of its cash contributions. The likelihood that the Project will be completed and, for 2020, the discount rate, are the most significant and sensitive assumptions; changes in these assumptions may materially change the results of the impairment calculation.

Based on the discounted cash flow analyses, Con Edison concluded as of December 31, 2020 and 2021 that the fair value of its investment in MVP declined below its carrying value and the declines were other-than-temporary. Accordingly, Con Edison recorded a pre-tax impairment loss of $320 million ($223 million, after tax) for the year ended December 31, 2020 that reduced the carrying value of its investment in MVP from $662 million to $342 million, with an associated deferred tax asset of $53 million. Additionally, Con Edison recorded a pre-tax

impairment loss of $231 million ($162 million, after tax) for the year ended December 31, 2021 that reduced the carrying value of its investment in MVP from $342 million to $111 million, with an additional $77 million associated deferred tax asset, totaling a deferred tax asset of $130 million at December 31, 2021 and 2022. The impairments were recorded within “Investment income (loss)” on Con Edison’s Consolidated Income Statement. In addition, Con Edison did not record non-cash equity in earnings from allowance for funds used during construction from MVP beginning in January 2021 and will continue to refrain from recording such amounts until such time as substantial construction activities resume, which would be indicative of probable Project completion. There were no impairments or substantial changes in the carrying value of Con Edison's investment in MVP for the

year ended December 31, 2022.

There is risk that the fair value of Con Edison’s investment in MVP may be further or fully impaired in the future. There are ongoing legal and regulatory matters that must be resolved favorably before the Project can be completed. Assumptions and estimates used to test Con Edison’s investment in MVP for impairment may change if adverse or delayed resolutions to the Project’s pending legal and regulatory challenges were to occur, which could have a material adverse effect on the fair value of Con Edison’s investment in MVP.

Pension and Other Postretirement Benefits

The accounting rules for retirement benefits require an employer to recognize an asset or liability for the overfunded or underfunded status of its pension and other postretirement benefit plans. For a pension plan, the asset or liability is the difference between the fair value of the plan’s assets and the projected benefit obligation. For any other postretirement benefit plan, the asset or liability is the difference between the fair value of the plan’s assets and the accumulated postretirement benefit obligation. The accounting rules generally require employers to recognize all unrecognized prior service costs and credits and unrecognized actuarial gains and losses in accumulated other comprehensive income/(loss) (OCI), net of tax. Such amounts will be adjusted as they are subsequently recognized as components of total periodic benefit cost or income pursuant to the current recognition and amortization provisions.

For the Utilities’ pension and other postretirement benefit plans, regulatory accounting treatment is generally applied in accordance with the accounting rules for regulated operations. Unrecognized prior service costs or credits and unrecognized actuarial gains and losses are recorded to regulatory assets or liabilities, rather than OCI. See Notes E and F.

The total periodic benefit costs are recognized in accordance with the accounting rules for retirement benefits. Investment gains and losses are recognized in expense over a 15-year period and other actuarial gains and losses are recognized in expense over a 10-year period, subject to the deferral provisions in the rate plans.

In accordance with the Statement of Policy issued by the NYSPSC and its current electric, gas and steam rate plans, CECONY defers for payment to or recovery from customers the difference between such expenses and the

amounts for such expenses reflected in rates. O&R also defers such difference pursuant to its NY rate plans. See Note B.

The Companies calculate the expected return on pension and other postretirement benefit plan assets by multiplying the expected rate of return on plan assets by the market-related value (MRV) of plan assets at the beginning of the year, taking into consideration anticipated contributions and benefit payments that are to be made during the year. The accounting rules allow the MRV of plan assets to be either fair value or a calculated value that recognizes changes in fair value in a systematic and rational manner over not more than five years. The Companies use a calculated value when determining the MRV of the plan assets that adjusts for 20 percent of the difference between fair value and expected MRV of plan assets. This calculated value has the effect of stabilizing variability in assets to which the Companies apply the expected return.

Federal Income Tax/State Income Tax

Federal Income Tax

In accordance with accounting rules for income taxes, the Companies have recorded an accumulated deferred federal income tax liability at current tax rates for temporary differences between the book and tax basis of assets and liabilities. In accordance with rate plans, the Utilities have recovered amounts from customers for a portion of the tax liability they will pay in the future as a result of the reversal or “turn-around” of these temporary differences. As to the remaining deferred tax liability, the Utilities had established regulatory assets for the net revenue requirements to be recovered from customers for the related future tax expense pursuant to the NYSPSC's 1993 Policy Statement approving accounting procedures consistent with accounting rules for income taxes and providing assurances that these future increases in taxes will be recoverable in rates.

Accumulated deferred investment tax credits are amortized ratably over the lives of the related properties and applied as a reduction to future federal income tax expense.

Con Edison and its subsidiaries file a consolidated federal income tax return. The consolidated income tax liability is allocated to each member of the consolidated group using the separate return method. Each member pays or receives an amount based on its own taxable income or loss in accordance with a consolidated tax allocation agreement. Tax loss and tax credit carryforwards are allocated among members in accordance with consolidated tax return regulations.

State Income Tax

Con Edison and its subsidiaries file a combined New York State Corporation Business Franchise Tax Return. Similar to a federal consolidated income tax return, the income of all entities in the combined group is subject to New York State taxation, after adjustments for differences between federal and New York law and apportionment of income among the states in which the company does business. Each member’s share of the New York State tax is based on its own New York State taxable income or loss.

Research and Development Costs

Research and Development CostsResearch and development costs are charged to operating expenses as incurred.

Reclassification

Certain prior period amounts have been reclassified within the Companies' Consolidated Statements of Cash Flows

and Consolidated Balance Sheets to conform with current period presentation.

Earnings Per Common Share

Con Edison presents basic and diluted earnings per share (EPS) on the face of its consolidated income statement. Basic EPS is calculated by dividing earnings available to common shareholders (“Net income for common stock” on Con Edison’s consolidated income statement) by the weighted average number of Con Edison common shares outstanding during the period. In the calculation of diluted EPS, weighted average shares outstanding are increased for additional shares that would be outstanding if potentially dilutive securities were converted to common stock.

Potentially dilutive securities for Con Edison consist of restricted stock units and deferred stock units for which the average market price of the common shares for the period was greater than the exercise price (see Note O) and its common shares that are subject to forward sale agreements (see Note C). Before the issuance of common shares upon settlement of the forward sale agreements, the shares will be reflected in the company’s diluted earnings per share calculations using the treasury stock method. Under this method, the number of common shares used in calculating diluted earnings per share is deemed to be increased by the excess, if any, of the number of shares that would be issued upon physical settlement of the forward sale agreements over the number of shares that could be purchased by the company in the market (based on the average market price during the period) using the proceeds due upon physical settlement (based on the adjusted forward sale price at the end of the reporting period).

Estimates

The preparation of financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and contingent assets and liabilities at the date of the financial statements and the reported amounts of revenues and expenses during the reporting period. Actual results could differ from those estimates.

New Financial Accounting Standards

In March 2020, the FASB issued ASU 2020-04, Reference Rate Reform (Topic 848): Facilitation of the Effects of Reference Rate Reform on Financial Reporting (ASU 2020-04). In 2017, the United Kingdom’s Financial Conduct Authority announced that it intends to stop persuading or compelling banks to submit the London Interbank Offered Rate (LIBOR), a benchmark interest rate referenced in a variety of agreements, after 2021. The United Kingdom's Financial Conduct Authority ceased publication of U.S. Dollar LIBOR after December 31, 2021 for one-week and two-month U.S. Dollar LIBOR tenors, and expects to cease publishing after June 30, 2023 for all other U.S. Dollar LIBOR tenors. ASU 2020-04 provides entities with optional expedients and exceptions for applying generally accepted accounting principles to contract modifications and hedging relationships, subject to meeting certain criteria, that reference LIBOR or another reference rate expected to be discontinued. In January 2021, the FASB issued amendments to the guidance through ASU 2021-01 to include all contract modifications and hedging relationships affected by reference rate reform, including those that do not directly reference LIBOR or another reference rate expected to be discontinued, and clarify which optional expedients may be applied to them. As the Companies continue to modify contracts that contain references to LIBOR that allow for the use of an alternative rate, they have applied the practical expedient to not assess each change for a contract modification. The guidance can be applied prospectively. The optional relief is temporary and generally cannot be applied to contract modifications and hedging relationships entered into or evaluated after December 31, 2024, which date reflects the updates in ASU 2022-06, Reference Rate Reform (Topic 848): Deferral of the Sunset Date of Topic 848. The Companies do not expect the guidance to have a material impact on their financial position, results of operations or liquidity.

In December 2021, the FASB issued amendments to the guidance on accounting for government assistance through ASU 2021-10, Government Assistance (Topic 832): Disclosures by Business Entities about Government Assistance. The amendments require that business entities that apply a grant or contribution model by analogy to other accounting guidance disclose 1) the types of assistance, 2) an entity’s accounting for the assistance, and 3) the effect of the assistance on an entity’s financial statements. For public entities, the amendments are effective for reporting periods beginning after December 15, 2021. Early adoption is permitted. The Companies have concluded the new guidance does not have a material impact on the Companies’ financial position, results of operations and liquidity.