PUBLIC SERVICE CO OF NEW MEXICO

The TXNM website is an important source of Company information. New or updated information for public access is routinely posted. TXNM encourages analysts, investors, and other interested parties to register on the website to automatically receive Company information by e-mail. This information includes news releases, notices of webcasts, and filings with the SEC. Participants will not receive information that was not requested and can unsubscribe at any time.

Our corporate websites are:

•TXNM: www.txnmenergy.com

•PNM: www.pnm.com

•TNMP: www.tnmp.com

TXNM’s corporate website includes a dedicated section providing key environmental and other sustainability information related to PNM’s and TNMP’s operations.

The contents of these websites are not a part of this Form 10-K and the inclusion of our website address in this report is an inactive textual reference only. The SEC filings of TXNM, PNM, and TNMP, including annual reports on Form 10-K, quarterly reports on Form 10-Q, current reports on Form 8-K, and amendments to those reports filed or furnished pursuant to Section 13(a) or 15(d) of the Exchange Act, are accessible free of charge on the TXNM website as soon as reasonably practicable after they are filed with, or furnished to, the SEC. Reports filed with the SEC are available on its website, www.sec.gov. These reports are also available in print upon request from TXNM free of charge.

Also available on the Company’s website athttps://www.txnmenergy.com/sustainability/governance/governance-documents and in print upon request from any shareholder are TXNM’s:

•Corporate Governance Principles

•Code of Ethics (Do the Right Thing–Principles of Business Conduct; Supplier Code of Conduct)

•Charters of the Audit and Ethics Committee, Nominating and Governance Committee, Compensation and Human Capital Committee, and Finance Committee

•Restated Articles of Incorporation and Bylaws

The Company will post amendments to or waivers from its code of ethics (to the extent applicable to the Company’s executive officers and directors) on its website.

OPERATIONS AND REGULATION

Regulated Operations

Electric power demand is generally seasonal. Power consumption in both Texas and New Mexico increases during the hot summer months with revenues traditionally peaking during that period. The seasonality of demand for electricity in turn impacts the timing of plant maintenance and operating expense throughout the year. As a result, the quarterly operating results of TXNM and its operating subsidiaries vary throughout the year. In addition, unusually mild or extreme weather patterns may cause the overall operating results of the Company to fluctuate. See Notes 16 and 17 for additional information on rate cases and other regulatory matters.

TNMP

Operational Information

TNMP is a regulated utility operating and incorporated in the State of Texas. TNMP’s predecessor was organized in 1925. 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, which is the independent system operator responsible for maintaining reliable operations for the bulk electric power supply system in most of Texas. Therefore, TNMP is not subject to traditional rate regulation by FERC. TNMP serves a market of small to medium sized communities, most of which have populations of less than 50,000. TNMP is the exclusive provider of transmission and distribution services in most areas it serves.

TNMP’s service territory consists of three non-contiguous areas. One portion of this territory extends from Lewisville, which is approximately 10 miles north of the Dallas-Fort Worth International Airport, eastward to municipalities near the Red River, and to communities north, west, and south of Fort Worth. The second portion of its service territory includes the area

A - 2 along the Texas Gulf Coast between Houston and Galveston, and the third portion includes areas of far west Texas between Midland and El Paso. TNMP owns 1,049 miles of electric transmission lines that interconnect with other utilities in Texas. There has been a significant increase in interconnection requests and data center applications on the TNMP system, which has necessitated new transmission stations, upgrades at existing stations, and transmission line capacity upgrades.

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. For its volumetric load consumers billed on KWh usage, TNMP experienced an increase of 2.8% in its weather normalized retail load in 2025 compared to 2024. For its weather normalized demand-based load, excluding retail transmission consumers, TNMP experienced an increase of 5.3% in 2025 compared to 2024. Data center load, including distribution and transmission, has increased 70.5% in 2025 compared to 2024. As of December 31, 2025, 125 active REPs receive transmission and distribution services from TNMP. In 2025, the two largest REPs accounted for 24% and 19% of TNMP’s operating revenues. No other consumer accounted for more than 10% of revenues.

TNMP holds long-term, non-exclusive franchise agreements for its electric transmission and distribution services. These agreements have varying expiration dates, and some have expired. TNMP intends to negotiate and execute new or amended franchise agreements with municipalities where the agreements have expired or will be expiring. Since TNMP is the exclusive provider of transmission and distribution services in most areas that it serves, the need to renew or renegotiate franchise agreements should not have a material adverse impact. TNMP also earns revenues from service provided to facilities in its service area that lie outside the territorial jurisdiction of the municipalities with which TNMP has franchise agreements.

Regulatory Activities

The rates TNMP charges customers are subject to traditional rate regulation by the PUCT. The PUCT has approved mechanisms that allow TNMP to recover capital invested in transmission and distribution projects without having to file a general rate case. The PUCT approved interim adjustments to TNMP’s transmission rates of $11.5 million annually in March 2025 and $12.3 million annually in September 2025. The PUCT approved interim adjustments to TNMP’s distribution rates of $25.0 million annually in June 2025 and $1.8 million annually in November 2025. The PUCT also approved rate riders that allow TNMP to recover amounts related to energy efficiency and third-party transmission costs.

In March 2025, the PUCT approved TNMP’s first SRP, designed to benefit customers through enhanced resiliency of its distribution system. The approved SRP includes $545.8 million of capital investments and $86.1 million of operations and maintenance expenses associated with several programs, including vegetation management and wildfire mitigation in 2025 through 2027.

In November 2025, TNMP filed the TNMP Base Rate Review with the PUCT, requesting recovery of $2.8 billion of rate base, a requested ROE of 10.4%, and a 47.54% equity ratio. The TNMP Base Rate Review also includes increases in operations and maintenance expenses that are not recovered through semi-annual TCOS and DCRF filings, excludes increases in interest expense resulting from refinancing of debt associated with the proposed Merger, and requests recovery of $20.5 million associated with Hurricane Beryl restoration costs over a five-year period. If approved by the PUCT, the new rates are expected to become effective in mid-2026.

PNM

Operational Information

PNM is an electric utility that provides electric generation, transmission, and distribution service to its rate-regulated customers. PNM was incorporated in the State of New Mexico in 1917. 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 as well as 9 sovereign nations. Service to retail electric customers is subject to the jurisdiction of the NMPRC. The largest retail electric customer served by PNM accounted for 5.4% of its retail electric revenues for the year ended December 31, 2025. Other services provided by PNM include wholesale transmission services to third parties. Regulation encompasses the utility’s electric rates, service, accounting, issuances of securities, construction of major new generation, abandonment of existing generation, types of generation resources, transmission and distribution facilities, and other matters. PNM experienced increases in weather normalized residential load of 0.1%, in commercial load of 1.0%, and industrial load of 14.3% compared to 2024. The system peak demands for retail customers are as follows:

System Peak Demands

PNM holds long-term, non-exclusive franchise agreements for its electric retail operations, with varying expiration dates. These franchise agreements allow the utility to access public rights-of-way for placement of its electric facilities. To the

A - 3 extent franchise agreements expire in some areas PNM serves, PNM remains obligated under New Mexico state law to provide service to customers in these areas, and therefore, the expirations should not have a material adverse impact. The Albuquerque, Rio Rancho, Los Lunas, and Santa Fe metropolitan areas accounted for 41.3%, 8.5%, 5.7% and 5.9% of PNM’s 2025 revenues. No other franchise area represents more than 5%. PNM also earns revenues from its electric retail operations in its service areas that do not require franchise agreements.

PNM owns 3,450 miles of electric transmission lines that interconnect with other utilities in New Mexico, Arizona, Colorado, Texas, and Utah. New Mexico is frequently characterized by its high potential for solar and wind capacity. PNM owns transmission capacity in an area of eastern New Mexico with large wind generation potential and in recent years there has been substantial interest by developers of wind generation to interconnect to PNM’s transmission system in this area.

Regulatory Activities

NMPRC Regulated Retail Rate Proceedings

On May 15, 2025, the NMPRC approved PNM’s general increase in retail electric rates. The approval includes an increase of $105.0 million in retail revenues with the first phase effective July 1, 2025, and the second phase effective April 1, 2026, reflecting an ROE of 9.45%.

In October 2024, the NMPRC approved PNM’s Grid Modernization Plan. PNM’s plan to modernize its electricity grid through infrastructure and technology improvements increases the efficiency, reliability, resilience, and security of PNM’s electric system. PNM’s grid modernization investments include approximately $344 million for the first six years of a broader 11-year strategy. The first annual Grid Modernization Plan review was approved in February 2026, updating key portions of the strategy, including increasing investments from approximately $344 million to $367 million for the first six years, and decreasing projected operations and maintenance costs by approximately 18%.

PNM has a NMPRC-approved rate rider to collect costs for renewable energy procurements that are not otherwise being collected in rates. The NMPRC has also approved riders designed to allow PNM to bill and collect substantially all fuel and purchased power costs, costs of approved energy efficiency initiatives, and costs associated with enhancing transportation electrification in New Mexico.

FERC Regulated Wholesale Transmission

Rates charged to wholesale electric transmission customers, other than customers on the Western Spirit Line, are based on a formula rate mechanism pursuant to which rates for wholesale transmission service are calculated annually in accordance with an approved formula. The formula includes updating cost of service components, including investment in plant and operating expenses, based on information contained in PNM’s annual financial report filed with FERC, as well as including projected transmission capital projects to be placed into service in the following year. The projections included are subject to true-up in the formula rate for the following year. Certain items, including changes to return on equity and depreciation rates, require a separate filing to be made with FERC before being included in the formula rate.

Renewable Energy

The REA was enacted to encourage the development of renewable energy in New Mexico. The ETA amended the REA and requires utilities operating in New Mexico to have renewable portfolios equal to 40% by 2025, 50% by 2030, 80% by 2040, and 100% zero-carbon energy by 2045. The REA provides for streamlined proceedings for approval of utilities’ renewable energy procurement plans, provides utilities recovery of costs incurred consistent with approved procurement plans, and sets a RCT for the procurement of renewable resources to prevent excessive costs being added to rates. PNM files required renewable energy plans with the NMPRC annually and makes procurements consistent with the plans approved by the NMPRC.