Summary of the Business and Significant Accounting Policies (Policies)	12 Months Ended
Dec. 31, 2022
Accounting Policies [Abstract]
Financial Statement Preparation and Presentation	Financial Statement Preparation and Presentation 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, disclosure of 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 ultimately differ from those estimated. The Notes to Consolidated Financial Statements include disclosures for PNMR, PNM, and TNMP. This report uses the term “Company” when discussing matters of common applicability to PNMR, PNM, and TNMP. Discussions regarding only PNMR, PNM, or TNMP are so indicated. Certain amounts in the 2021 and 2020 Consolidated Financial Statements and Notes thereto have been reclassified to conform to the 2022 financial statement presentation. GAAP defines subsequent events as events or transactions that occur after the balance sheet date but before financial statements are issued or are available to be issued. Based on their nature, magnitude, and timing, certain subsequent events may be required to be reflected at the balance sheet date and/or required to be disclosed in the financial statements. The Company has evaluated subsequent events accordingly.
Principles of Consolidation	Principles of Consolidation The Consolidated Financial Statements of each of PNMR, PNM, and TNMP include their accounts and those of subsidiaries in which that entity owns a majority voting interest. PNM also consolidates Valencia (Note 10). PNM owns undivided interests in jointly-owned power plants and records its pro-rata share of the assets, liabilities, and expenses for those plants. The agreements for the jointly-owned plants provide that if an owner were to default on its payment obligations, the non-defaulting owners would be responsible for their proportionate share of the obligations of the defaulting owner. In exchange, the non-defaulting owners would be entitled to their proportionate share of the generating capacity of the defaulting owner. There have been no such payment defaults under any of the agreements for the jointly-owned plants. PNMR Services Company expenses, which represent costs that are primarily driven by corporate level activities, are charged to the business segments. These services are billed at cost and are reflected as general and administrative expenses in the business segments. Other significant intercompany transactions between PNMR, PNM, and TNMP include intercompany loans, interest and income tax sharing payments, as well as equity transactions, and interconnection billings. All intercompany transactions and balances have been eliminated.
Accounting for the Effects of Certain Types of Regulation	Accounting for the Effects of Certain Types of Regulation The Company maintains its accounting records in accordance with the uniform system of accounts prescribed by FERC and adopted by the NMPRC and PUCT. Certain of the Company’s operations are regulated by the NMPRC, PUCT, and FERC and the provisions of GAAP for rate-regulated enterprises are applied to the regulated operations. Regulators may assign costs to accounting periods that differ from accounting methods applied by non-regulated utilities. When it is probable that regulators will permit recovery of costs through future rates, costs are deferred as regulatory assets that otherwise would be expensed. Likewise, regulatory liabilities are recognized when it is probable that regulators will require refunds through future rates or when revenue is collected for expenditures that have not yet been incurred. GAAP also provides for the recognition of revenue and regulatory assets and liabilities associated with “alternative revenue programs” authorized by regulators. Such programs allow the utility to adjust future rates in response to past activities or completed events, if certain criteria are met. Regulatory assets and liabilities are amortized into earnings over the authorized recovery period. Accordingly, the Company has deferred certain costs and recorded certain liabilities pursuant to the rate actions of the NMPRC, PUCT, and FERC. Information on regulatory assets and regulatory liabilities is contained in Note 13. In some circumstances, regulators allow a requested increase in rates to be implemented, subject to refund, before the regulatory process has been completed and a decision rendered by the regulator. When this occurs, the Company assesses the possible outcomes of the rate proceeding. The Company records a provision for refund to the extent the amounts being collected, subject to refund, exceed the amount the Company determines is probable of ultimately being allowed by the regulator.
Cash and Restricted Cash	Cash and Restricted Cash Cash deposits received and held for a period of time that are restricted to a specific purpose, under the terms of their effective agreements, are considered restricted cash. Investments in highly liquid investments with original maturities of three months or less at the date of purchase are considered cash and cash equivalents. At December 31, 2022 and 2021 there was no restricted cash for PNMR, PNM, and TNMP.
Utility Plant	Utility Plant Utility plant is stated at original cost and includes capitalized payroll-related costs such as taxes, pension, other fringe benefits, administrative costs, and AFUDC, where authorized by rate regulation, or capitalized interest. Repairs, including major maintenance activities, and minor replacements of property are expensed when incurred, except as required by regulators for ratemaking purposes. Major replacements are charged to utility plant. Gains, losses, and costs to remove resulting from retirements or other dispositions of regulated property in the normal course of business are credited or charged to accumulated depreciation. PNM and TNMP may receive reimbursements, referred to as CIAC, from customers to pay for all or part of certain construction projects to the extent the project does not benefit regulated customers in general. PNM and TNMP account for these reimbursements as offsets to utility plant additions based on the requirements of the NMPRC, FERC, and PUCT. Due to the PUCT’s regulatory treatment of CIAC reimbursements, TNMP also receives a financing component that is recognized as other income on the Consolidated Statements of Earnings. Under the NMPRC regulatory treatment, PNM typically does not receive a financing component.
Depreciation and Amortization	Depreciation and AmortizationPNM’s provision for depreciation and amortization of utility plant, other than nuclear fuel, is based upon straight-line rates approved by the NMPRC and FERC. Amortization of nuclear fuel is based on units-of-production. TNMP’s provision for depreciation and amortization of utility plant is based upon straight-line rates approved by the PUCT. Depreciation and amortization of non-utility property, including right-of-use assets for finance leases as discussed in Note 8, is computed based on the straight-line method. The provision for depreciation of certain equipment is allocated between operating expenses and construction projects based on the use of the equipment.
Allowance for Funds Used During Construction	Allowance for Funds Used During Construction As provided by the FERC uniform systems of accounts, AFUDC is charged to regulated utility plant for construction projects. This allowance is designed to enable a utility to capitalize financing costs during periods of construction of property subject to rate regulation. It represents the cost of borrowed funds (allowance for borrowed funds used during construction or “debt AFUDC”) and a return on other funds (allowance for equity funds used during construction or “equity AFUDC”). The debt AFUDC is recorded in interest charges and the equity AFUDC is recorded in other income on the Consolidated Statements of Earnings.
Materials, Supplies, and Fuel Stock	Materials, Supplies, and Fuel StockMaterials and supplies relate to transmission, distribution, and generating assets. Materials and supplies are charged to inventory when purchased and are expensed or capitalized as appropriate when issued. Materials and supplies are valued using an average costing method. Coal is valued using a rolling weighted average costing method that is updated based on the current period cost per ton. Average cost is equal to net realizable value under the ratemaking process.
Investments	Investments PNM holds investment securities in the NDT for the purpose of funding its share of the decommissioning costs of PVNGS, a trust for PNM’s share of decommissioning costs at SJGS, and trusts for PNM’s share of final reclamation costs related to the coal mines that served SJGS and continue to serve Four Corners (Note 16). Investments (both equity and available-for-sale debt securities) are measured at fair value on a quarterly basis with changes in fair value for equity securities recognized in earnings for that period. Since third party investment managers have sole discretion over the purchase and sale of the securities (under general guidelines and targets provided by management), PNM records an impairment, as a realized loss, for any available-for-sale debt security that has a fair value which is less than cost at the end of each quarter. For the years ended December 31, 2022, 2021 and 2020, PNM recorded impairment losses on the available-for-sale debt securities of $25.8 million, $(0.7) million and $3.2 million. No gains or losses are deferred as regulatory assets or liabilities. See Notes 3 and 9. All investments are held in PNM’s name and are in the custody of major financial institutions. The specific identification method is used to determine the cost of securities disposed of, with realized gains and losses reflected in other income and deductions. As discussed above, PNM immediately records an impairment loss for any available-for-sale debt security that has a fair value that is less than its carrying value. As a result, the Company has no available-for-sale debt securities for which carrying value exceeds fair value and there are no impairments considered to be “other than temporary” that are included in AOCI and not recognized in earnings. All gains and losses resulting from sales and changes in the fair value of equity securities are recognized immediately in earnings.
Equity Method Investment	Equity Method InvestmentPNMR accounts for its investment in NMRD using the equity method of accounting because PNMR’s ownership interest results in significant influence, but not control, over NMRD and its operations. PNMR records as income its percentage share of earnings or loss of NMRD and carries its investment at cost, adjusted for its share of undistributed earnings or losses.
Goodwill	Goodwill The Company does not amortize goodwill. Goodwill is evaluated for impairment annually, or more frequently if events and circumstances indicate that the goodwill might be impaired.
Asset Impairment	Asset Impairment Tangible long-lived assets and right-of-use assets associated with leases are evaluated in relation to the estimated future undiscounted cash flows to assess recoverability when events and circumstances indicate that the assets might be impaired.
Amortization of Debt Acquisition Costs	Amortization of Debt Acquisition Costs Discount, premium, and expense related to the issuance of long-term debt are amortized over the lives of the respective issues. Gains and losses incurred upon the early retirement of long-term debt are recognized in other income or other deductions, except for amounts recoverable through NMPRC, FERC, or PUCT regulation, which are recorded as regulatory assets or liabilities and amortized over the lives of the respective issues. Unamortized premium, discount, and expense related to long-term debt are reflected as part of the related liability on the Consolidated Balance Sheets.
Derivatives	Derivatives The Company records derivative instruments, including energy contracts, on the balance sheet as either an asset or liability measured at their fair value. Changes in the derivatives’ fair value are recognized in earnings unless specific hedge accounting criteria are met. PNM also records certain commodity derivative transactions recoverable through NMPRC regulation as regulatory assets or liabilities. See Note 9. The Company treats all forward commodity purchases and sales contracts subject to unplanned netting or “book-out” by the transmission provider as derivative instruments subject to mark-to-market accounting. GAAP provides guidance on whether realized gains and losses on derivative contracts not held for trading purposes should be reported on a net or gross basis and concludes such classification is a matter of judgment that depends on the relevant facts and circumstances. Accounting for Derivatives Under derivative accounting and related rules for energy contracts, PNM accounts for its various instruments for the purchase and sale of energy, which meet the definition of a derivative, based on PNM’s intent. During the years ended December 31, 2022, 2021, and 2020, PNM was not hedging its exposure to the variability in future cash flows from commodity derivatives through designated cash flow hedges. The derivative contracts recorded at fair value that do not qualify or are not designated for cash flow hedge accounting are classified as economic hedges. Economic hedges are defined as derivative instruments, including long-term power agreements, used to economically hedge generation assets, purchased power and fuel costs, and customer load requirements. Changes in the fair value of economic hedges are reflected in results of operations and are classified between operating revenues and cost of energy according to the intent of the hedge. PNM also uses such instruments under an NMPRC approved hedging plan to manage fuel and purchased power costs related to customers covered by its FPPAC. Changes in the fair value of instruments covered by its FPPAC are recorded as regulatory assets and liabilities. PNM has no trading transactions.
Decommissioning and Reclamation Costs	Decommissioning and Reclamation Costs PNM is only required to recognize and measure decommissioning liabilities for tangible long-lived assets for which a legal obligation exists. Nuclear decommissioning costs and related accruals are based on periodic site-specific estimates of the costs for removing all radioactive and other structures at PVNGS and are dependent upon numerous assumptions, including estimates of future decommissioning costs at current price levels, inflation rates, and discount rates. PNM’s accruals for PVNGS Units 1, 2, and 3, including portions held under leases, have been made based on such estimates, the guidelines of the NRC, and the PVNGS license periods. PNM records its share of the SJGS decommissioning obligation as an ARO on its Consolidated Balance Sheets. Studies on the decommissioning costs of SJGS are performed periodically and revisions to the ARO liability are recorded. See Note 16. In connection with both the SJGS and Four Corners coal supply agreements, the owners are required to reimburse the mining companies for the cost of contemporaneous reclamation, as well as the costs for final reclamation of the coal mines. The reclamation costs are based on periodic site-specific studies that estimate the costs to be incurred in the future and are dependent upon numerous assumptions, including estimates of future reclamation costs at current price levels, inflation rates, and discount rates. PNM considers the contemporaneous reclamation costs part of the cost of its delivered coal costs.
Environmental Costs	Environmental Costs The normal operations of the Company involve activities and substances that expose the Company to potential liabilities under laws and regulations protecting the environment. Liabilities under these laws and regulations can be material and may be imposed without regard to fault, or may be imposed for past acts, even though the past acts may have been lawful at the time they occurred. The Company records its environmental liabilities when site assessments or remedial actions are probable and a range of reasonably likely cleanup costs can be estimated. The Company reviews its sites and measures the liability by assessing a range of reasonably likely costs for each identified site using currently available information and the probable level of involvement and financial condition of other potentially responsible parties. These estimates are based on assumptions regarding the costs for site investigations, remediation, operations and maintenance, monitoring, and site closure. The ultimate cost to clean up the Company’s identified sites may vary from its recorded liability due to numerous uncertainties inherent in the estimation process.
Income Taxes	Income Taxes Income taxes are recognized using the asset and liability method of accounting for income taxes. Deferred tax assets and liabilities are recognized for the estimated future tax consequences attributable to differences between the financial statement carrying value of existing assets and liabilities and their respective tax basis. All deferred taxes are reflected as non-current on the Consolidated Balance Sheets. Current NMPRC, FERC, and PUCT approved rates include the tax effects of the majority of these differences. Rate-regulated enterprises are required to record deferred income taxes for temporary differences accorded flow-through treatment at the direction of a regulatory commission. The resulting deferred tax assets and liabilities are recorded based on the expected cash flow to be reflected in future rates. Because the NMPRC, FERC, and the PUCT have consistently permitted the recovery of tax effects previously flowed-through earnings, the Company has established regulatory assets and liabilities offsetting such deferred tax assets and liabilities. The Company recognizes only the impact of tax positions that, based on their merits, are more likely than not to be sustained upon an IRS audit. The Company defers investment tax credits and amortizes them over the estimated useful lives of the assets. See Note 18 for additional information, including a discussion of the impacts of the Tax Act. The Company makes an estimate of its anticipated effective tax rate for the year as of the end of each quarterly period within its fiscal year. In interim periods, income tax expense is calculated by applying the anticipated annual effective tax rate to year-to-date earnings before taxes. Certain unusual or infrequently occurring items, as well as adjustments due to enactment of new tax laws, have been excluded from the estimated annual effective tax rate calculation.
New Accounting Pronouncements	New Accounting Pronouncements Information concerning a recently issued accounting pronouncement that has not yet been adopted by the Company is presented below. The Company does not expect difficulty in adopting this standard by its required effective date. Accounting Standards Update 2022-03 - Fair Value Measurement (Topic 820): Fair Value Measurements of Equity Securities Subject to Contractual Sale Restrictions In June 2022, the FASB issued ASU 2022-03 clarifying that a contractual restriction on the sale of an equity security is not considered part of the unit of account of the security and, therefore, is not considered in measuring fair value. The amendment also clarifies that an entity cannot, as a separate unit of account, recognize and measure a contractual sale restriction. Disclosure requirements from the amendment include disclosure of the fair value of equity securities subject to contractual sale restrictions that are reflected in the balance sheet; the nature and remaining duration of the restriction(s); and the circumstances that could cause a lapse in the restriction(s). ASU 2022-03 is effective for the Company beginning January 1, 2024 with early adoption for both interim and annual periods being permitted. ASU 2022-03 is to be applied prospectively with any adjustments recognized in earnings and disclosed on the date of adoption.
Segment Information	The following segment presentation is based on the methodology that management uses for making operating decisions and assessing performance of its various business activities. A reconciliation of the segment presentation to the GAAP financial statements is provided. PNM PNM includes the retail electric utility operations of PNM that are subject to traditional rate regulation by the NMPRC. PNM provides integrated electricity services that include the generation, transmission, and distribution of electricity for retail electric customers in New Mexico. PNM also includes the generation and sale of electricity into the wholesale market, as well as providing transmission services to third parties. The sale of electricity includes the asset optimization of PNM’s jurisdictional capacity as well as the capacity excluded from retail rates through 2022. FERC has jurisdiction over wholesale power and transmission rates. TNMP TNMP is an electric utility providing services in Texas under the TECA. TNMP’s operations are subject to traditional rate regulation by the PUCT. TNMP provides transmission and distribution services at regulated rates to various REPs that, in turn, provide retail electric service to consumers within TNMP’s service area. TNMP also provides transmission services at regulated rates to other utilities that interconnect with TNMP’s facilities. Corporate and Other The Corporate and Other segment includes PNMR holding company activities, primarily related to corporate level debt and PNMR Services Company. The activities of PNMR Development and the equity method investment in NMRD are also included in Corporate and Other. Eliminations of intercompany transactions are reflected in the Corporate and Other segment.
Revenue Recognition	Retail electric operating revenues are recorded in the period of energy delivery, which includes estimated amounts for service rendered but unbilled at the end of each accounting period. The determination of the energy sales billed to individual retail customers is based on the reading of their meters, which occurs on a systematic basis throughout the month. At the end of each month, amounts of energy delivered to customers since the date of the last meter reading and the corresponding unbilled revenue are estimated. Unbilled electric revenue is estimated based on daily generation volumes, estimated customer usage by class, line losses, historical trends and experience, applicable customer rates or by using AMS data where available. Amounts billed are generally due within the next month. The Company does not incur incremental costs to obtain contracts for its energy services. PNM’s wholesale electricity sales are recorded as electric operating revenues and wholesale electricity purchases are recorded as costs of energy sold. Derivative contracts that are subject to unplanned netting are recorded net in earnings. A “book-out” is the planned or unplanned netting of off-setting purchase and sale transactions. A book-out is a transmission mechanism to reduce congestion on the transmission system or administrative burden. For accounting purposes, a book-out is the recording of net revenues upon the settlement of a derivative contract. Unrealized gains and losses on derivative contracts that are not designated for hedge accounting are classified as economic hedges. Economic hedges are defined as derivative instruments, including long-term power and fuel supply agreements, used to hedge generation assets and purchased power costs. Changes in the fair value of economic hedges are reflected in results of operations, with changes related to economic hedges on sales included in operating revenues and changes related to economic hedges on purchases included in cost of energy sold. See Note 9. The Company has collaborative arrangements related to its interest in SJGS, Four Corners, PVNGS, and Luna. The Company has determined that during the years ended December 31, 2022, 2021, and 2020 none of the joint owners in its collaborative arrangements were customers under Topic 606. The Company will continue to evaluate transactions between collaborative arrangement participants in future periods under the revenue recognition standard. PNM and TNMP recognize revenue as they satisfy performance obligations, which typically occurs as the customer or end-user consumes the electric service provided. Electric services are typically for a bundle of services that are distinct and transferred to the end-user in one performance obligation measured by KWh or KW. Electric operating revenues are recorded in the period of energy delivery, including estimated unbilled amounts. The Company has elected to exclude all sales and similar taxes from revenue. Revenue from contracts with customers is recorded based upon the total authorized tariff or market price at the time electric service is rendered, including amounts billed under arrangements qualifying as an Alternative Revenue Program (“ARP”). ARP arrangements are agreements between PNM or TNMP and its regulator that allow PNM or TNMP to adjust future rates in response to past activities or completed events, if certain criteria are met. ARP revenues are required to be reported separately from contracts with customers. ARP revenues in a given period include the recognition of “originating” ARP revenues (i.e. when the regulator-specific conditions are met) in the period, offset by the reversal of ARP revenues when billed to customers. Sources of Revenue Additional information about the nature of revenues is provided below. Additional information about matters affecting PNM’s and TNMP’s regulated revenues is provided in Note 17. Revenue from Contracts with Customers PNM NMPRC Regulated Retail Electric Service – PNM provides electric generation, transmission, and distribution service to its rate-regulated customers in New Mexico. PNM’s retail electric service territory covers a large area of north central New Mexico, including the cities of Albuquerque, Rio Rancho, and Santa Fe, and certain areas of southern New Mexico. Customer rates for retail electric service are set by the NMPRC and revenue is recognized as energy is delivered to the customer. PNM invoices customers on a monthly basis for electric service and generally collects billed amounts within one month. Transmission Service to Third Parties – PNM owns transmission lines that are interconnected with other utilities in New Mexico, Texas, Arizona, Colorado, and Utah. Transmission customers receive service for the transmission of energy owned by the customer utilizing PNM’s transmission facilities. Customers generally receive transmission services, which are regulated by FERC, from PNM through PNM’s Open Access Transmission Tariff (“OATT”) or a specific contract. Customers are billed based on capacity and energy components on a monthly basis. In December 2021, PNM completed the purchase of the Western Spirit Line and services under related transmission agreements were initiated using an incremental rate, approved by FERC, that are separate from the formula rate mechanism. Wholesale Energy Sales – PNM engages in activities to optimize its existing jurisdictional assets and long-term power agreements through spot market, hour-ahead, day-ahead, week-ahead, month-ahead, and other sales of excess generation not required to fulfill retail load and contractual commitments. PNM began participating in the EIM in 2021. The EIM is a real-time wholesale energy trading market operated by the CAISO that enables participating electric utilities to buy and sell energy. The NMPRC granted PNM authority to seek recovery of costs associated with joining the EIM, which have been included in the 2024 Rate Change and to pass the benefits of participating in EIM to customers through the FPPAC. PNM’s participation in EIM has significantly increased Electric operating revenues which are passed on to customers under PNM’s FPPAC with no impact to net earnings. Beginning on January 1, 2018, PNM acquired a 65 MW interest in SJGS Unit 4, which was held as merchant plant as ordered by the NMPRC. PNM sold power from 36 MW of this capacity to a third party at a fixed price that was recorded as revenue from contracts with customers. PNM was obligated to deliver power under this arrangement only when SJGS Unit 4 was operating. In May 2022, PNM executed a new agreement to sell 50 MW of that capacity to a third party for the period from July 1, 2022 through September 30, 2022 on a system-contingent basis. TNMP PUCT Regulated Retail Electric Service – TNMP provides transmission and distribution services in Texas under the provisions of TECA and the Texas Public Utility Regulatory Act. TNMP is subject to traditional cost-of-service regulation with respect to rates and service under the jurisdiction of the PUCT and certain municipalities. TNMP’s transmission and distribution activities are solely within ERCOT and not subject to traditional rate regulation by FERC. TNMP provides transmission and distribution services at regulated rates to various REPs that, in turn, provide retail electric service to consumers within TNMP’s service territory. Revenue is recognized as energy is delivered to the consumer. TNMP invoices REPs on a monthly basis and is generally paid within a month. TCOS – TNMP is a transmission service provider that is allowed to recover its TCOS through a network transmission rate that is approved by the PUCT. TCOS customers are other utilities that receive service for the transmission of energy owned by the customer utilizing TNMP’s transmission facilities. Alternative Revenue Programs The Company defers certain costs and records certain liabilities pursuant to the rate actions of the NMPRC, PUCT, and FERC. ARP revenues, which are discussed above, include recovery or refund provisions under PNM’s renewable energy rider and true-ups to PNM’s formula transmission rates; TNMP’s AMS surcharge, transmission cost recovery factor, and the impacts of the PUCT’s January 25, 2018 order regarding the change in the federal corporate income tax rate; and the energy efficiency incentive bonus at both PNM and TNMP. Regulatory assets and liabilities are recognized for the difference between ARP revenues and amounts billed under those programs. Regulatory assets and liabilities are amortized into earnings as amounts are billed. TNMP’s 2018 Rate Case integrated AMS costs into base rates beginning January 1, 2019. These costs are being amortized into earnings as alternative revenues over a period of five years. Other Electric Operating Revenues Other electric operating revenues consist primarily of PNM’s economic hedges that meet the definition of a derivative, and are therefore not considered revenue from contracts with customers. Derivative revenues include gains and losses representing changes in fair value (Note 9) and settlements from sales of electricity under forward sales contracts.
Accounts Receivable and Allowance for Credit Losses	Accounts Receivable and Allowance for Credit LossesAccounts receivable consists primarily of trade receivables from customers. In the normal course of business, credit is extended to customers on a short-term basis. The Company estimates the allowance for credit losses on trade receivables based on historical experience and estimated default rates. Accounts receivable balances are reviewed monthly, adjustments to the allowance for credit losses are made as necessary and amounts that are deemed uncollectible are written off.
Fair Value of Derivatives	The Company determines the fair values of its derivative and other financial instruments based on the hierarchy, which requires an entity to maximize the use of observable inputs and minimize the use of unobservable inputs when measuring fair value. There are three levels of inputs that may be used to measure fair value. Level 1 inputs are quoted prices (unadjusted) in active markets for identical assets or liabilities that the reporting entity has the ability to access at the measurement date. Level 2 inputs are inputs other than quoted prices included within Level 1 that are observable for the asset or liability, either directly or indirectly. Level 3 inputs are unobservable inputs for the asset or liability. For investment securities, Level 2 and Level 3 fair values are provided by fund managers utilizing a pricing service. For Level 2 fair values, the pricing provider predominantly uses the market approach using bid side market values based upon a hierarchy of information for specific securities or securities with similar characteristics. Fair values of Level 2 investments in mutual funds are equal to net asset value. For commodity derivatives, Level 2 fair values are determined based on market observable inputs, which are validated using multiple broker quotes, including forward price, volatility, and interest rate curves to establish expectations of future prices. Credit valuation adjustments are made for estimated credit losses based on the overall exposure to each counterparty. For the Company’s long-term debt, Level 2 fair values are provided by an external pricing service. The pricing service primarily utilizes quoted prices for similar debt in active markets when determining fair value. The valuation of Level 3 investments, when applicable, requires significant judgment by the pricing provider due to the absence of quoted market values, changes in market conditions, and the long-term nature of the assets. The Company has no Level 3 investments as of December 31, 2022 and 2021. Management of the Company independently verifies the information provided by pricing services.
Variable Interest Entities	How an enterprise evaluates and accounts for its involvement with variable interest entities, focuses primarily on whether the enterprise has the power to direct the activities that most significantly impact the economic performance of a variable interest entity (“VIE”). This evaluation requires continual reassessment of the primary beneficiary of a VIE.
Pension and Other Postretirement Benefits	PNMR and its subsidiaries maintain qualified defined benefit pension plans, postretirement benefit plans providing medical and dental benefits, and executive retirement programs (collectively, the “PNM Plans” and “TNMP Plans”). PNMR maintains the legal obligation for the benefits owed to participants under these plans. The periodic costs or income of the PNM Plans and TNMP Plans are included in regulated rates to the extent attributable to regulated operations. PNM and TNMP receive a regulated return on the amounts funded for pension and OPEB plans in excess of the periodic cost or income to the extent included in retail rates (a “prepaid pension asset”). Participants in the PNM Plans include eligible employees and retirees of PNMR and PNM. Participants in the TNMP Plans include eligible employees and retirees of TNMP. The PNM pension plan was frozen at the end of 1997 with regard to new participants, salary levels, and benefits. Through December 31, 2007, additional credited service could be accrued under the PNM pension plan up to a limit determined by age and service. The TNMP pension plan was frozen at December 31, 2005 with regard to new participants, salary levels, and benefits. A plan sponsor is required to (a) recognize in its statement of financial position an asset for a plan’s overfunded status or a liability for a plan’s underfunded status; (b) measure a plan’s assets and its obligations that determine its funded status as of the end of the employer’s fiscal year; and (c) recognize changes in the funded status of a defined benefit postretirement plan in the year in which the changes occur. Unrecognized prior service costs and unrecognized gains or losses are required to be recorded in AOCI and subsequently amortized. To the extent the amortization of these items will ultimately be recovered or returned through future rates, PNM and TNMP record the costs as a regulatory asset or regulatory liability. The amortization of these incurred costs is included as pension and postretirement benefit periodic cost or income in subsequent years. The Company maintains trust funds for the pension and OPEB plans from which benefits are paid to eligible employees and retirees. The Company’s funding policy is to make contributions to the trusts, as determined by an independent actuary, that comply with minimum guidelines of the Employee Retirement Income Security Act and the IRC. Information concerning the fair value of investments is contained in Note 9. The Company has in place a policy that defines the investment objectives, establishes performance goals of asset managers, and provides procedures for the manner in which investments are to be reviewed. The plans implement investment strategies to achieve the following objectives: •Implement investment strategies commensurate with the risk that the Corporate Investment Committee deems appropriate to meet the obligations of the pension plans and OPEB plans, minimize the volatility of expense, and account for contingencies •Transition asset mix over the long-term to a higher proportion of high-quality fixed income investments as the plans’ funded statuses improve Management is responsible for the determination of the asset target mix and the expected rate of return. The target asset allocations are determined based on consultations with external investment advisors. The expected long-term rate of return on pension and postretirement plan assets is calculated on the market-related value of assets. Actual gains and losses on pension and OPEB plan assets are recognized in the market-related value of assets equally over a period of not more than five years, which reduces year-to-year volatility. For the PNM Plans and TNMP Plans, the market-related value of assets is equal to the prior year’s market-related value of assets adjusted for contributions, benefit payments and investment gains and losses that are within a corridor of plus or minus 4.0% around the expected return on market value. Gains and losses that are outside the corridor are amortized over five years.
Commitments and Contingencies	There are various claims and lawsuits pending against the Company. In addition, the Company is subject to federal, state, and local environmental laws and regulations and periodically participates in the investigation and remediation of various sites. In addition, the Company periodically enters into financial commitments in connection with its business operations. Also, the Company is involved in various legal and regulatory proceedings in the normal course of its business. See Note 17. It is not possible at this time for the Company to determine fully the effect of all litigation and other legal and regulatory proceedings on its financial position, results of operations, or cash flows. With respect to some of the items listed below, the Company has determined that a loss is not probable or that, to the extent probable, cannot be reasonably estimated. In some cases, the Company is not able to predict with any degree of certainty the range of possible loss that could be incurred. The Company assesses legal and regulatory matters based on current information and makes judgments concerning their potential outcome, giving due consideration to the nature of the claim, the amount and nature of any damages sought, and the probability of success. Such judgments are made with the understanding that the outcome of any litigation, investigation, or other legal proceeding is inherently uncertain. The Company records liabilities for matters where it is probable a loss has been incurred and the amount of loss is reasonably estimable. The actual outcomes of the items listed below could ultimately differ from the judgments made and the differences could be material. The Company cannot make any assurances that the amount of reserves or potential insurance coverage will be sufficient to cover the cash obligations that might be incurred as a result of litigation or regulatory proceedings. Except as otherwise disclosed, the Company does not expect that any known lawsuits, environmental costs, or commitments will have a material effect on its financial condition, results of operations, or cash flows.

Summary of the Business and Significant Accounting Policies (Policies)

12 Months Ended

Dec. 31, 2022

Financial Statement Preparation and Presentation

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, disclosure of 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 ultimately differ from those estimated.

The Notes to Consolidated Financial Statements include disclosures for PNMR, PNM, and TNMP. This report uses the term “Company” when discussing matters of common applicability to PNMR, PNM, and TNMP. Discussions regarding only PNMR, PNM, or TNMP are so indicated.

Certain amounts in the 2021 and 2020 Consolidated Financial Statements and Notes thereto have been reclassified to conform to the 2022 financial statement presentation.

GAAP defines subsequent events as events or transactions that occur after the balance sheet date but before financial statements are issued or are available to be issued. Based on their nature, magnitude, and timing, certain subsequent events may be required to be reflected at the balance sheet date and/or required to be disclosed in the financial statements. The Company has evaluated subsequent events accordingly.

Principles of Consolidation

The Consolidated Financial Statements of each of PNMR, PNM, and TNMP include their accounts and those of subsidiaries in which that entity owns a majority voting interest. PNM also consolidates Valencia (Note 10). PNM owns undivided interests in jointly-owned power plants and records its pro-rata share of the assets, liabilities, and expenses for those plants. The agreements for the jointly-owned plants provide that if an owner were to default on its payment obligations, the non-defaulting owners would be responsible for their proportionate share of the obligations of the defaulting owner. In exchange, the non-defaulting owners would be entitled to their proportionate share of the generating capacity of the defaulting owner. There have been no such payment defaults under any of the agreements for the jointly-owned plants.

PNMR Services Company expenses, which represent costs that are primarily driven by corporate level activities, are charged to the business segments. These services are billed at cost and are reflected as general and administrative expenses in the business segments. Other significant intercompany transactions between PNMR, PNM, and TNMP include intercompany loans, interest and income tax sharing payments, as well as equity transactions, and interconnection billings. All intercompany transactions and balances have been eliminated.

Accounting for the Effects of Certain Types of Regulation

The Company maintains its accounting records in accordance with the uniform system of accounts prescribed by FERC and adopted by the NMPRC and PUCT.

Certain of the Company’s operations are regulated by the NMPRC, PUCT, and FERC and the provisions of GAAP for rate-regulated enterprises are applied to the regulated operations. Regulators may assign costs to accounting periods that differ from accounting methods applied by non-regulated utilities. When it is probable that regulators will permit recovery of costs through future rates, costs are deferred as regulatory assets that otherwise would be expensed. Likewise, regulatory liabilities are recognized when it is probable that regulators will require refunds through future rates or when revenue is collected for

expenditures that have not yet been incurred. GAAP also provides for the recognition of revenue and regulatory assets and liabilities associated with “alternative revenue programs” authorized by regulators. Such programs allow the utility to adjust future rates in response to past activities or completed events, if certain criteria are met. Regulatory assets and liabilities are amortized into earnings over the authorized recovery period. Accordingly, the Company has deferred certain costs and recorded certain liabilities pursuant to the rate actions of the NMPRC, PUCT, and FERC. Information on regulatory assets and regulatory liabilities is contained in Note 13.

In some circumstances, regulators allow a requested increase in rates to be implemented, subject to refund, before the regulatory process has been completed and a decision rendered by the regulator. When this occurs, the Company assesses the possible outcomes of the rate proceeding. The Company records a provision for refund to the extent the amounts being collected, subject to refund, exceed the amount the Company determines is probable of ultimately being allowed by the regulator.

Cash and Restricted Cash

Cash deposits received and held for a period of time that are restricted to a specific purpose, under the terms of their effective agreements, are considered restricted cash. Investments in highly liquid investments with original maturities of three months or less at the date of purchase are considered cash and cash equivalents. At December 31, 2022 and 2021 there was no restricted cash for PNMR, PNM, and TNMP.

Utility Plant

Utility plant is stated at original cost and includes capitalized payroll-related costs such as taxes, pension, other fringe benefits, administrative costs, and AFUDC, where authorized by rate regulation, or capitalized interest.

Repairs, including major maintenance activities, and minor replacements of property are expensed when incurred, except as required by regulators for ratemaking purposes. Major replacements are charged to utility plant. Gains, losses, and costs to remove resulting from retirements or other dispositions of regulated property in the normal course of business are credited or charged to accumulated depreciation.

PNM and TNMP may receive reimbursements, referred to as CIAC, from customers to pay for all or part of certain construction projects to the extent the project does not benefit regulated customers in general. PNM and TNMP account for these reimbursements as offsets to utility plant additions based on the requirements of the NMPRC, FERC, and PUCT. Due to the PUCT’s regulatory treatment of CIAC reimbursements, TNMP also receives a financing component that is recognized as other income on the Consolidated Statements of Earnings. Under the NMPRC regulatory treatment, PNM typically does not receive a financing component.

Depreciation and Amortization

Depreciation and AmortizationPNM’s provision for depreciation and amortization of utility plant, other than nuclear fuel, is based upon straight-line rates approved by the NMPRC and FERC. Amortization of nuclear fuel is based on units-of-production. TNMP’s provision for depreciation and amortization of utility plant is based upon straight-line rates approved by the PUCT. Depreciation and amortization of non-utility property, including right-of-use assets for finance leases as discussed in Note 8, is computed based on the straight-line method. The provision for depreciation of certain equipment is allocated between operating expenses and construction projects based on the use of the equipment.

Allowance for Funds Used During Construction

As provided by the FERC uniform systems of accounts, AFUDC is charged to regulated utility plant for construction projects. This allowance is designed to enable a utility to capitalize financing costs during periods of construction of property subject to rate regulation. It represents the cost of borrowed funds (allowance for borrowed funds used during construction or

“debt AFUDC”) and a return on other funds (allowance for equity funds used during construction or “equity AFUDC”). The debt AFUDC is recorded in interest charges and the equity AFUDC is recorded in other income on the Consolidated Statements of Earnings.

Materials, Supplies, and Fuel Stock

Materials, Supplies, and Fuel StockMaterials and supplies relate to transmission, distribution, and generating assets. Materials and supplies are charged to inventory when purchased and are expensed or capitalized as appropriate when issued. Materials and supplies are valued using an average costing method. Coal is valued using a rolling weighted average costing method that is updated based on the current period cost per ton. Average cost is equal to net realizable value under the ratemaking process.

Investments

PNM holds investment securities in the NDT for the purpose of funding its share of the decommissioning costs of PVNGS, a trust for PNM’s share of decommissioning costs at SJGS, and trusts for PNM’s share of final reclamation costs related to the coal mines that served SJGS and continue to serve Four Corners (Note 16). Investments (both equity and available-for-sale debt securities) are measured at fair value on a quarterly basis with changes in fair value for equity securities recognized in earnings for that period. Since third party investment managers have sole discretion over the purchase and sale of the securities (under general guidelines and targets provided by management), PNM records an impairment, as a realized loss, for any available-for-sale debt security that has a fair value which is less than cost at the end of each quarter. For the years ended December 31, 2022, 2021 and 2020, PNM recorded impairment losses on the available-for-sale debt securities of $25.8 million, $(0.7) million and $3.2 million. No gains or losses are deferred as regulatory assets or liabilities. See Notes 3 and 9. All investments are held in PNM’s name and are in the custody of major financial institutions. The specific identification method is used to determine the cost of securities disposed of, with realized gains and losses reflected in other income and deductions.

As discussed above, PNM immediately records an impairment loss for any available-for-sale debt security that has a fair value that is less than its carrying value. As a result, the Company has no available-for-sale debt securities for which carrying value exceeds fair value and there are no impairments considered to be “other than temporary” that are included in AOCI and not recognized in earnings. All gains and losses resulting from sales and changes in the fair value of equity securities are recognized immediately in earnings.

Equity Method Investment

Equity Method InvestmentPNMR accounts for its investment in NMRD using the equity method of accounting because PNMR’s ownership interest results in significant influence, but not control, over NMRD and its operations. PNMR records as income its percentage share of earnings or loss of NMRD and carries its investment at cost, adjusted for its share of undistributed earnings or losses.

Goodwill

Goodwill The Company does not amortize goodwill. Goodwill is evaluated for impairment annually, or more frequently if events and circumstances indicate that the goodwill might be impaired.

Asset Impairment

Tangible long-lived assets and right-of-use assets associated with leases are evaluated in relation to the estimated future undiscounted cash flows to assess recoverability when events and circumstances indicate that the assets might be impaired.

Amortization of Debt Acquisition Costs

Discount, premium, and expense related to the issuance of long-term debt are amortized over the lives of the respective issues. Gains and losses incurred upon the early retirement of long-term debt are recognized in other income or other deductions, except for amounts recoverable through NMPRC, FERC, or PUCT regulation, which are recorded as regulatory assets or liabilities and amortized over the lives of the respective issues. Unamortized premium, discount, and expense related to long-term debt are reflected as part of the related liability on the Consolidated Balance Sheets.

Derivatives

The Company records derivative instruments, including energy contracts, on the balance sheet as either an asset or liability measured at their fair value. Changes in the derivatives’ fair value are recognized in earnings unless specific hedge accounting criteria are met. PNM also records certain commodity derivative transactions recoverable through NMPRC regulation as regulatory assets or liabilities. See Note 9.

The Company treats all forward commodity purchases and sales contracts subject to unplanned netting or “book-out” by the transmission provider as derivative instruments subject to mark-to-market accounting. GAAP provides guidance on whether realized gains and losses on derivative contracts not held for trading purposes should be reported on a net or gross basis and concludes such classification is a matter of judgment that depends on the relevant facts and circumstances.

Accounting for Derivatives

Under derivative accounting and related rules for energy contracts, PNM accounts for its various instruments for the purchase and sale of energy, which meet the definition of a derivative, based on PNM’s intent. During the years ended December 31, 2022, 2021, and 2020, PNM was not hedging its exposure to the variability in future cash flows from commodity derivatives through designated cash flow hedges. The derivative contracts recorded at fair value that do not qualify or are not designated for cash flow hedge accounting are classified as economic hedges. Economic hedges are defined as derivative instruments, including long-term power agreements, used to economically hedge generation assets, purchased power and fuel costs, and customer load requirements. Changes in the fair value of economic hedges are reflected in results of operations and are classified between operating revenues and cost of energy according to the intent of the hedge. PNM also uses such instruments under an NMPRC approved hedging plan to manage fuel and purchased power costs related to customers covered by its FPPAC. Changes in the fair value of instruments covered by its FPPAC are recorded as regulatory assets and liabilities. PNM has no trading transactions.

Decommissioning and Reclamation Costs

PNM is only required to recognize and measure decommissioning liabilities for tangible long-lived assets for which a legal obligation exists. Nuclear decommissioning costs and related accruals are based on periodic site-specific estimates of the costs for removing all radioactive and other structures at PVNGS and are dependent upon numerous assumptions, including estimates of future decommissioning costs at current price levels, inflation rates, and discount rates. PNM’s accruals for PVNGS Units 1, 2, and 3, including portions held under leases, have been made based on such estimates, the guidelines of the NRC, and the PVNGS license periods. PNM records its share of the SJGS decommissioning obligation as an ARO on its Consolidated Balance Sheets. Studies on the decommissioning costs of SJGS are performed periodically and revisions to the ARO liability are recorded. See Note 16.

In connection with both the SJGS and Four Corners coal supply agreements, the owners are required to reimburse the mining companies for the cost of contemporaneous reclamation, as well as the costs for final reclamation of the coal mines. The reclamation costs are based on periodic site-specific studies that estimate the costs to be incurred in the future and are dependent upon numerous assumptions, including estimates of future reclamation costs at current price levels, inflation rates, and discount rates. PNM considers the contemporaneous reclamation costs part of the cost of its delivered coal costs.

Environmental Costs

The normal operations of the Company involve activities and substances that expose the Company to potential liabilities under laws and regulations protecting the environment. Liabilities under these laws and regulations can be material and may be imposed without regard to fault, or may be imposed for past acts, even though the past acts may have been lawful at the time they occurred.

The Company records its environmental liabilities when site assessments or remedial actions are probable and a range of reasonably likely cleanup costs can be estimated. The Company reviews its sites and measures the liability by assessing a range of reasonably likely costs for each identified site using currently available information and the probable level of involvement and financial condition of other potentially responsible parties. These estimates are based on assumptions regarding the costs for site investigations, remediation, operations and maintenance, monitoring, and site closure. The ultimate cost to clean up the Company’s identified sites may vary from its recorded liability due to numerous uncertainties inherent in the estimation process.

Income Taxes

Income taxes are recognized using the asset and liability method of accounting for income taxes. Deferred tax assets and liabilities are recognized for the estimated future tax consequences attributable to differences between the financial statement carrying value of existing assets and liabilities and their respective tax basis. All deferred taxes are reflected as non-current on the Consolidated Balance Sheets. Current NMPRC, FERC, and PUCT approved rates include the tax effects of the majority of these differences. Rate-regulated enterprises are required to record deferred income taxes for temporary differences accorded flow-through treatment at the direction of a regulatory commission. The resulting deferred tax assets and liabilities are recorded based on the expected cash flow to be reflected in future rates. Because the NMPRC, FERC, and the PUCT have consistently permitted the recovery of tax effects previously flowed-through earnings, the Company has established regulatory assets and liabilities offsetting such deferred tax assets and liabilities. The Company recognizes only the impact of tax positions that, based on their merits, are more likely than not to be sustained upon an IRS audit. The Company defers investment tax credits and amortizes them over the estimated useful lives of the assets. See Note 18 for additional information, including a discussion of the impacts of the Tax Act.

The Company makes an estimate of its anticipated effective tax rate for the year as of the end of each quarterly period within its fiscal year. In interim periods, income tax expense is calculated by applying the anticipated annual effective tax rate to year-to-date earnings before taxes. Certain unusual or infrequently occurring items, as well as adjustments due to enactment of new tax laws, have been excluded from the estimated annual effective tax rate calculation.

New Accounting Pronouncements

Information concerning a recently issued accounting pronouncement that has not yet been adopted by the Company is presented below. The Company does not expect difficulty in adopting this standard by its required effective date.

Accounting Standards Update 2022-03 - Fair Value Measurement (Topic 820): Fair Value Measurements of Equity Securities Subject to Contractual Sale Restrictions

In June 2022, the FASB issued ASU 2022-03 clarifying that a contractual restriction on the sale of an equity security is not considered part of the unit of account of the security and, therefore, is not considered in measuring fair value. The amendment also clarifies that an entity cannot, as a separate unit of account, recognize and measure a contractual sale restriction. Disclosure requirements from the amendment include disclosure of the fair value of equity securities subject to contractual sale restrictions that are reflected in the balance sheet; the nature and remaining duration of the restriction(s); and the circumstances that could cause a lapse in the restriction(s). ASU 2022-03 is effective for the Company beginning January 1, 2024 with early adoption for both interim and annual periods being permitted. ASU 2022-03 is to be applied prospectively with any adjustments recognized in earnings and disclosed on the date of adoption.

Segment Information

The following segment presentation is based on the methodology that management uses for making operating decisions and assessing performance of its various business activities. A reconciliation of the segment presentation to the GAAP financial statements is provided.

PNM

PNM includes the retail electric utility operations of PNM that are subject to traditional rate regulation by the NMPRC. PNM provides integrated electricity services that include the generation, transmission, and distribution of electricity for retail electric customers in New Mexico. PNM also includes the generation and sale of electricity into the wholesale market, as well as providing transmission services to third parties. The sale of electricity includes the asset optimization of PNM’s jurisdictional capacity as well as the capacity excluded from retail rates through 2022. FERC has jurisdiction over wholesale power and transmission rates.

TNMP

TNMP is an electric utility providing services in Texas under the TECA. TNMP’s operations are subject to traditional rate regulation by the PUCT. TNMP provides transmission and distribution services at regulated rates to various REPs that, in turn, provide retail electric service to consumers within TNMP’s service area. TNMP also provides transmission services at regulated rates to other utilities that interconnect with TNMP’s facilities.

Corporate and Other

The Corporate and Other segment includes PNMR holding company activities, primarily related to corporate level debt and PNMR Services Company. The activities of PNMR Development and the equity method investment in NMRD are also included in Corporate and Other. Eliminations of intercompany transactions are reflected in the Corporate and Other segment.

Revenue Recognition

Retail electric operating revenues are recorded in the period of energy delivery, which includes estimated amounts for service rendered but unbilled at the end of each accounting period. The determination of the energy sales billed to individual retail customers is based on the reading of their meters, which occurs on a systematic basis throughout the month. At the end of each month, amounts of energy delivered to customers since the date of the last meter reading and the corresponding unbilled revenue are estimated. Unbilled electric revenue is estimated based on daily generation volumes, estimated customer usage by class, line losses, historical trends and experience, applicable customer rates or by using AMS data where available. Amounts billed are generally due within the next month. The Company does not incur incremental costs to obtain contracts for its energy services.

PNM’s wholesale electricity sales are recorded as electric operating revenues and wholesale electricity purchases are recorded as costs of energy sold. Derivative contracts that are subject to unplanned netting are recorded net in earnings. A “book-out” is the planned or unplanned netting of off-setting purchase and sale transactions. A book-out is a transmission mechanism to reduce congestion on the transmission system or administrative burden. For accounting purposes, a book-out is the recording of net revenues upon the settlement of a derivative contract.

Unrealized gains and losses on derivative contracts that are not designated for hedge accounting are classified as economic hedges. Economic hedges are defined as derivative instruments, including long-term power and fuel supply agreements, used to hedge generation assets and purchased power costs. Changes in the fair value of economic hedges are reflected in results of operations, with changes related to economic hedges on sales included in operating revenues and changes related to economic hedges on purchases included in cost of energy sold. See Note 9.

The Company has collaborative arrangements related to its interest in SJGS, Four Corners, PVNGS, and Luna. The Company has determined that during the years ended December 31, 2022, 2021, and 2020 none of the joint owners in its collaborative arrangements were customers under Topic 606. The Company will continue to evaluate transactions between collaborative arrangement participants in future periods under the revenue recognition standard.

PNM and TNMP recognize revenue as they satisfy performance obligations, which typically occurs as the customer or end-user consumes the electric service provided. Electric services are typically for a bundle of services that are distinct and transferred to the end-user in one performance obligation measured by KWh or KW. Electric operating revenues are recorded in the period of energy delivery, including estimated unbilled amounts. The Company has elected to exclude all sales and similar taxes from revenue.

Revenue from contracts with customers is recorded based upon the total authorized tariff or market price at the time electric service is rendered, including amounts billed under arrangements qualifying as an Alternative Revenue Program (“ARP”). ARP arrangements are agreements between PNM or TNMP and its regulator that allow PNM or TNMP to adjust future rates in response to past activities or completed events, if certain criteria are met. ARP revenues are required to be reported separately from contracts with customers. ARP revenues in a given period include the recognition of “originating” ARP revenues (i.e. when the regulator-specific conditions are met) in the period, offset by the reversal of ARP revenues when billed to customers.

Sources of Revenue

Additional information about the nature of revenues is provided below. Additional information about matters affecting PNM’s and TNMP’s regulated revenues is provided in Note 17.

Revenue from Contracts with Customers

PNM

NMPRC Regulated Retail Electric Service – PNM provides electric generation, transmission, and distribution service to its rate-regulated customers in New Mexico. PNM’s retail electric service territory covers a large area of north central New Mexico, including the cities of Albuquerque, Rio Rancho, and Santa Fe, and certain areas of southern New Mexico. Customer rates for retail electric service are set by the NMPRC and revenue is recognized as energy is delivered to the customer. PNM invoices customers on a monthly basis for electric service and generally collects billed amounts within one month.

Transmission Service to Third Parties – PNM owns transmission lines that are interconnected with other utilities in New Mexico, Texas, Arizona, Colorado, and Utah. Transmission customers receive service for the transmission of energy owned by the customer utilizing PNM’s transmission facilities. Customers generally receive transmission services, which are regulated by FERC, from PNM through PNM’s Open Access Transmission Tariff (“OATT”) or a specific contract. Customers are billed based on capacity and energy components on a monthly basis. In December 2021, PNM completed the purchase of the Western Spirit Line and services under related transmission agreements were initiated using an incremental rate, approved by FERC, that are separate from the formula rate mechanism.

Wholesale Energy Sales – PNM engages in activities to optimize its existing jurisdictional assets and long-term power agreements through spot market, hour-ahead, day-ahead, week-ahead, month-ahead, and other sales of excess generation not required to fulfill retail load and contractual commitments. PNM began participating in the EIM in 2021. The EIM is a real-time wholesale energy trading market operated by the CAISO that enables participating electric utilities to buy and sell energy. The NMPRC granted PNM authority to seek recovery of costs associated with joining the EIM, which have been included in the 2024 Rate Change and to pass the benefits of participating in EIM to customers through the FPPAC. PNM’s participation in EIM has significantly increased Electric operating revenues which are passed on to customers under PNM’s FPPAC with no impact to net earnings.

Beginning on January 1, 2018, PNM acquired a 65 MW interest in SJGS Unit 4, which was held as merchant plant as ordered by the NMPRC. PNM sold power from 36 MW of this capacity to a third party at a fixed price that was recorded as revenue from contracts with customers. PNM was obligated to deliver power under this arrangement only when SJGS Unit 4 was operating. In May 2022, PNM executed a new agreement to sell 50 MW of that capacity to a third party for the period from July 1, 2022 through September 30, 2022 on a system-contingent basis.

TNMP

PUCT Regulated Retail Electric Service – TNMP provides transmission and distribution services in Texas under the provisions of TECA and the Texas Public Utility Regulatory Act. TNMP is subject to traditional cost-of-service regulation with respect to rates and service under the jurisdiction of the PUCT and certain municipalities. TNMP’s transmission and distribution activities are solely within ERCOT and not subject to traditional rate regulation by FERC. TNMP provides transmission and distribution services at regulated rates to various REPs that, in turn, provide retail electric service to consumers within TNMP’s service territory. Revenue is recognized as energy is delivered to the consumer. TNMP invoices REPs on a monthly basis and is generally paid within a month.

TCOS – TNMP is a transmission service provider that is allowed to recover its TCOS through a network transmission rate that is approved by the PUCT. TCOS customers are other utilities that receive service for the transmission of energy owned by the customer utilizing TNMP’s transmission facilities.

Alternative Revenue Programs

The Company defers certain costs and records certain liabilities pursuant to the rate actions of the NMPRC, PUCT, and FERC. ARP revenues, which are discussed above, include recovery or refund provisions under PNM’s renewable energy rider and true-ups to PNM’s formula transmission rates; TNMP’s AMS surcharge, transmission cost recovery factor, and the impacts of the PUCT’s January 25, 2018 order regarding the change in the federal corporate income tax rate; and the energy efficiency incentive bonus at both PNM and TNMP. Regulatory assets and liabilities are recognized for the difference between ARP

revenues and amounts billed under those programs. Regulatory assets and liabilities are amortized into earnings as amounts are billed. TNMP’s 2018 Rate Case integrated AMS costs into base rates beginning January 1, 2019. These costs are being amortized into earnings as alternative revenues over a period of five years.

Other Electric Operating Revenues

Other electric operating revenues consist primarily of PNM’s economic hedges that meet the definition of a derivative, and are therefore not considered revenue from contracts with customers. Derivative revenues include gains and losses representing changes in fair value (Note 9) and settlements from sales of electricity under forward sales contracts.

Accounts Receivable and Allowance for Credit Losses

Accounts Receivable and Allowance for Credit LossesAccounts receivable consists primarily of trade receivables from customers. In the normal course of business, credit is extended to customers on a short-term basis. The Company estimates the allowance for credit losses on trade receivables based on historical experience and estimated default rates. Accounts receivable balances are reviewed monthly, adjustments to the allowance for credit losses are made as necessary and amounts that are deemed uncollectible are written off.

Fair Value of Derivatives

The Company determines the fair values of its derivative and other financial instruments based on the hierarchy, which requires an entity to maximize the use of observable inputs and minimize the use of unobservable inputs when measuring fair value. There are three levels of inputs that may be used to measure fair value. Level 1 inputs are quoted prices (unadjusted) in active markets for identical assets or liabilities that the reporting entity has the ability to access at the measurement date. Level 2 inputs are inputs other than quoted prices included within Level 1 that are observable for the asset or liability, either directly or indirectly. Level 3 inputs are unobservable inputs for the asset or liability. For investment securities, Level 2 and Level 3 fair values are provided by fund managers utilizing a pricing service. For Level 2 fair values, the pricing provider predominantly uses the market approach using bid side market values based upon a hierarchy of information for specific securities or securities with similar characteristics. Fair values of Level 2 investments in mutual funds are equal to net asset value. For commodity derivatives, Level 2 fair values are determined based on market observable inputs, which are validated using multiple broker quotes, including forward price, volatility, and interest rate curves to establish expectations of future prices. Credit valuation adjustments are made for estimated credit losses based on the overall exposure to each counterparty. For the Company’s long-term debt, Level 2 fair values are provided by an external pricing service. The pricing service primarily utilizes quoted prices for similar debt in active markets when determining fair value. The valuation of Level 3 investments, when applicable, requires significant judgment by the pricing provider due to the absence of quoted market values, changes in market conditions, and the long-term nature of the assets. The Company has no Level 3 investments as of December 31, 2022 and 2021. Management of the Company independently verifies the information provided by pricing services.

Variable Interest Entities

How an enterprise evaluates and accounts for its involvement with variable interest entities, focuses primarily on whether the enterprise has the power to direct the activities that most significantly impact the economic performance of a variable interest entity (“VIE”). This evaluation requires continual reassessment of the primary beneficiary of a VIE.

Pension and Other Postretirement Benefits

PNMR and its subsidiaries maintain qualified defined benefit pension plans, postretirement benefit plans providing medical and dental benefits, and executive retirement programs (collectively, the “PNM Plans” and “TNMP Plans”). PNMR maintains the legal obligation for the benefits owed to participants under these plans. The periodic costs or income of the PNM Plans and TNMP Plans are included in regulated rates to the extent attributable to regulated operations. PNM and TNMP receive a regulated return on the amounts funded for pension and OPEB plans in excess of the periodic cost or income to the extent included in retail rates (a “prepaid pension asset”).

Participants in the PNM Plans include eligible employees and retirees of PNMR and PNM. Participants in the TNMP Plans include eligible employees and retirees of TNMP. The PNM pension plan was frozen at the end of 1997 with regard to new participants, salary levels, and benefits. Through December 31, 2007, additional credited service could be accrued under the PNM pension plan up to a limit determined by age and service. The TNMP pension plan was frozen at December 31, 2005 with regard to new participants, salary levels, and benefits.

A plan sponsor is required to (a) recognize in its statement of financial position an asset for a plan’s overfunded status or a liability for a plan’s underfunded status; (b) measure a plan’s assets and its obligations that determine its funded status as of the end of the employer’s fiscal year; and (c) recognize changes in the funded status of a defined benefit postretirement plan in the year in which the changes occur.

Unrecognized prior service costs and unrecognized gains or losses are required to be recorded in AOCI and subsequently amortized. To the extent the amortization of these items will ultimately be recovered or returned through future rates, PNM and TNMP record the costs as a regulatory asset or regulatory liability. The amortization of these incurred costs is included as pension and postretirement benefit periodic cost or income in subsequent years.

The Company maintains trust funds for the pension and OPEB plans from which benefits are paid to eligible employees and retirees. The Company’s funding policy is to make contributions to the trusts, as determined by an independent actuary, that comply with minimum guidelines of the Employee Retirement Income Security Act and the IRC. Information concerning the fair value of investments is contained in Note 9. The Company has in place a policy that defines the investment objectives, establishes performance goals of asset managers, and provides procedures for the manner in which investments are to be reviewed. The plans implement investment strategies to achieve the following objectives:

•Implement investment strategies commensurate with the risk that the Corporate Investment Committee deems appropriate to meet the obligations of the pension plans and OPEB plans, minimize the volatility of expense, and account for contingencies

•Transition asset mix over the long-term to a higher proportion of high-quality fixed income investments as the plans’ funded statuses improve

Management is responsible for the determination of the asset target mix and the expected rate of return. The target asset allocations are determined based on consultations with external investment advisors. The expected long-term rate of return on pension and postretirement plan assets is calculated on the market-related value of assets. Actual gains and losses on pension and OPEB plan assets are recognized in the market-related value of assets equally over a period of not more than five years, which reduces year-to-year volatility. For the PNM Plans and TNMP Plans, the market-related value of assets is equal to the prior year’s market-related value of assets adjusted for contributions, benefit payments and investment gains and losses that are within a corridor of plus or minus 4.0% around the expected return on market value. Gains and losses that are outside the corridor are amortized over five years.

Commitments and Contingencies

There are various claims and lawsuits pending against the Company. In addition, the Company is subject to federal, state, and local environmental laws and regulations and periodically participates in the investigation and remediation of various sites. In addition, the Company periodically enters into financial commitments in connection with its business operations. Also, the Company is involved in various legal and regulatory proceedings in the normal course of its business. See Note 17. It is not possible at this time for the Company to determine fully the effect of all litigation and other legal and regulatory proceedings on its financial position, results of operations, or cash flows.

With respect to some of the items listed below, the Company has determined that a loss is not probable or that, to the extent probable, cannot be reasonably estimated. In some cases, the Company is not able to predict with any degree of certainty the range of possible loss that could be incurred. The Company assesses legal and regulatory matters based on current information and makes judgments concerning their potential outcome, giving due consideration to the nature of the claim, the amount and nature of any damages sought, and the probability of success. Such judgments are made with the understanding that the outcome of any litigation, investigation, or other legal proceeding is inherently uncertain. The Company records

liabilities for matters where it is probable a loss has been incurred and the amount of loss is reasonably estimable. The actual outcomes of the items listed below could ultimately differ from the judgments made and the differences could be material. The Company cannot make any assurances that the amount of reserves or potential insurance coverage will be sufficient to cover the cash obligations that might be incurred as a result of litigation or regulatory proceedings. Except as otherwise disclosed, the Company does not expect that any known lawsuits, environmental costs, or commitments will have a material effect on its financial condition, results of operations, or cash flows.