Description of Business and Basis of Presentation	6 Months Ended
Jun. 30, 2026
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Description of Business and Basis of Presentation [Text Block]	Note 1 – Description of Business and Basis of Presentation Description of Business Williams Williams is a Delaware corporation whose common stock is listed and traded on the New York Stock Exchange. Its operations are located in the United States and are presented within the following reportable segments: Transmission, Power & Gulf; Northeast G&P; West; and Gas & NGL Marketing Services, consistent with the manner in which Williams’ Chief Executive Officer, the chief operating decision maker (CODM), evaluates performance and allocates resources. All remaining business activities, including upstream operations and corporate activities, are included in Other. Transmission, Power & Gulf is comprised of interstate natural gas pipelines and their related natural gas storage facilities, including Transco, NWP, MountainWest Pipelines Holding LLC (MountainWest), and a 50 percent equity-method investment in Gulfstream Natural Gas System, L.L.C. (Gulfstream); natural gas gathering and processing (G&P) and crude oil production handling and transportation assets in the Gulf Coast region; and natural gas storage facilities and pipelines providing services in north Texas, Louisiana, and Mississippi. Transmission, Power & Gulf also includes power innovation projects under development that will deliver speed-to-market solutions in power grid-constrained markets. Northeast G&P is comprised of Williams’ midstream gathering, processing, and fractionation businesses in the Marcellus Shale region primarily in Pennsylvania and New York, and the Utica Shale region of eastern Ohio, as well as a 65 percent interest in Ohio Valley Midstream LLC (Northeast JV) (a consolidated variable interest entity, or VIE) which operates in West Virginia, Ohio, and Pennsylvania, a 66 percent interest in Cardinal Gas Services, L.L.C. (Cardinal) (a consolidated VIE) which operates in Ohio, a 50 percent equity-method investment in Blue Racer Midstream LLC (Blue Racer), and Appalachia Midstream Investments. West is comprised of Williams’ gas gathering, processing, and treating operations in the Denver-Julesberg Basin (DJ Basin) and Piceance regions of Colorado, the southwest and Wamsutter regions of Wyoming, the Barnett Shale region of north-central Texas, the Eagle Ford Shale region of south Texas, and the Haynesville Shale region of east Texas and northwest Louisiana. In the first quarter of 2026, the Anadarko basin gathering assets in the Mid-Continent region were sold (see Note 3 – Divestitures). This segment also includes Williams’ NGL storage facilities, an undivided 50 percent interest in a NGL fractionator near Conway, Kansas, and a 50 percent equity-method investment in Overland Pass Pipeline Company LLC (OPPL). Gas & NGL Marketing Services is comprised of Williams’ NGL and natural gas marketing and trading operations, which include risk management and transactions related to the storage and transportation of natural gas and NGLs on strategically positioned assets, as well as an equity-method investment in Cogentrix Co-Investment Fund, LP (Cogentrix) (a nonconsolidated VIE), representing an approximate 10 percent indirect interest in 11 natural gas power plants. Transco Transco is an interstate natural gas transmission company that owns and operates an interstate natural gas pipeline system extending from Texas, Louisiana, Mississippi and the Gulf of America through Alabama, Georgia, South Carolina, North Carolina, Virginia, Maryland, Delaware, Pennsylvania, and New Jersey to the New York City metropolitan area. The system serves customers in Texas and the 12 southeast and Atlantic seaboard states mentioned above, including major metropolitan areas in Georgia, Washington D.C., Maryland, North Carolina, New York, New Jersey, and Pennsylvania. Transco is a single-member limited liability company, and as such, single-member losses are limited to the amount of its investment. NWP NWP owns and operates an interstate pipeline system for the mainline transmission of natural gas. This system extends from the San Juan Basin in northwestern New Mexico and southwestern Colorado through Colorado, Utah, Wyoming, Idaho, Oregon, and Washington to a point on the Canadian border near Sumas, Washington. NWP is a single-member limited liability company, and as such, single-member losses are limited to the amount of its investment. Basis of Presentation The accompanying interim financial statements do not include all the notes in the annual financial statements and, therefore, should be read in conjunction with the financial statements and combined notes thereto for the year ended December 31, 2025, in the Annual Report on Form 10-K. The accompanying unaudited financial statements include all normal recurring adjustments and others that, in the opinion of management, are necessary to present fairly the interim financial statements. The preparation of financial statements in conformity with accounting principles generally accepted in the United States requires management to make estimates and assumptions that affect the amounts reported in the financial statements and accompanying combined notes. Actual results could differ from those estimates. Significant Risks and Uncertainties Management believes that the carrying value of certain of Williams’ property, plant, and equipment and intangible assets, notably certain assets acquired by Williams accounted for as business combinations between 2012 and 2014, may be in excess of current fair value. However, the carrying value of these assets, in management’s judgment, continues to be recoverable. It is reasonably possible that future strategic decisions, including transactions such as monetizing assets or contributing assets to new ventures with third parties, as well as unfavorable changes in expected producer activities, could impact management’s assumptions and ultimately result in impairments of these assets. Such transactions or developments may also indicate that certain Williams’ equity-method investments have experienced other-than-temporary declines in value, which could result in impairment. Accounting Standards Issued But Not Yet Adopted In November 2024, the Financial Accounting Standards Board (FASB) issued Accounting Standards Update (ASU) 2024-03, Income Statement - Reporting Comprehensive Income - Expense Disaggregation Disclosures, which requires public entities to disclose additional information in the notes to financial statements for certain types of expenses (including purchases of inventory, employee compensation, depreciation, amortization, and depletion) in commonly presented expense captions (such as cost of sales or general and administrative expenses). The amendments are effective for fiscal years beginning after December 15, 2026, and interim periods within those fiscal years beginning after December 15, 2027, with early adoption permitted. The impact of this standard is currently being evaluated. In May 2026, the FASB issued ASU 2026-02, Environmental Credits and Environmental Credit Obligations, which establishes guidance for the recognition, measurement, presentation, and disclosure of environmental credits and related obligations. The amendments are effective for fiscal years beginning after December 15, 2027, and interim periods within those fiscal years, with early adoption permitted. The impact of this standard is currently being evaluated and is expected to primarily relate to NWP's compliance with the Washington State Climate Commitment Act.

Williams is a Delaware corporation whose common stock is listed and traded on the New York Stock Exchange. Its operations are located in the United States and are presented within the following reportable segments: Transmission, Power & Gulf; Northeast G&P; West; and Gas & NGL Marketing Services, consistent with the manner in which Williams’ Chief Executive Officer, the chief operating decision maker (CODM), evaluates performance and allocates resources. All remaining business activities, including upstream operations and corporate activities, are included in Other.

Transmission, Power & Gulf is comprised of interstate natural gas pipelines and their related natural gas storage facilities, including Transco, NWP, MountainWest Pipelines Holding LLC (MountainWest), and a 50 percent equity-method investment in Gulfstream Natural Gas System, L.L.C. (Gulfstream); natural gas gathering and processing (G&P) and crude oil production handling and transportation assets in the Gulf Coast region; and natural gas storage facilities and pipelines providing services in north Texas, Louisiana, and Mississippi. Transmission, Power & Gulf also includes power innovation projects under development that will deliver speed-to-market solutions in power grid-constrained markets.

Northeast G&P is comprised of Williams’ midstream gathering, processing, and fractionation businesses in the Marcellus Shale region primarily in Pennsylvania and New York, and the Utica Shale region of eastern Ohio, as well as a 65 percent interest in Ohio Valley Midstream LLC (Northeast JV) (a consolidated variable interest entity, or VIE) which operates in West Virginia, Ohio, and Pennsylvania, a 66 percent interest in Cardinal Gas Services,

L.L.C. (Cardinal) (a consolidated VIE) which operates in Ohio, a 50 percent equity-method investment in Blue Racer Midstream LLC (Blue Racer), and Appalachia Midstream Investments.

West is comprised of Williams’ gas gathering, processing, and treating operations in the Denver-Julesberg Basin (DJ Basin) and Piceance regions of Colorado, the southwest and Wamsutter regions of Wyoming, the Barnett Shale region of north-central Texas, the Eagle Ford Shale region of south Texas, and the Haynesville Shale region of east Texas and northwest Louisiana. In the first quarter of 2026, the Anadarko basin gathering assets in the Mid-Continent region were sold (see Note 3 – Divestitures). This segment also includes Williams’ NGL storage facilities, an undivided 50 percent interest in a NGL fractionator near Conway, Kansas, and a 50 percent equity-method investment in Overland Pass Pipeline Company LLC (OPPL).

Gas & NGL Marketing Services is comprised of Williams’ NGL and natural gas marketing and trading operations, which include risk management and transactions related to the storage and transportation of natural gas and NGLs on strategically positioned assets, as well as an equity-method investment in Cogentrix Co-Investment Fund, LP (Cogentrix) (a nonconsolidated VIE), representing an approximate 10 percent indirect interest in 11 natural gas power plants.

Transco is an interstate natural gas transmission company that owns and operates an interstate natural gas pipeline system extending from Texas, Louisiana, Mississippi and the Gulf of America through Alabama, Georgia, South Carolina, North Carolina, Virginia, Maryland, Delaware, Pennsylvania, and New Jersey to the New York City metropolitan area. The system serves customers in Texas and the 12 southeast and Atlantic seaboard states mentioned above, including major metropolitan areas in Georgia, Washington D.C., Maryland, North Carolina, New York, New Jersey, and Pennsylvania. Transco is a single-member limited liability company, and as such, single-member losses are limited to the amount of its investment.

NWP owns and operates an interstate pipeline system for the mainline transmission of natural gas. This system extends from the San Juan Basin in northwestern New Mexico and southwestern Colorado through Colorado, Utah, Wyoming, Idaho, Oregon, and Washington to a point on the Canadian border near Sumas, Washington. NWP is a single-member limited liability company, and as such, single-member losses are limited to the amount of its investment.

The accompanying interim financial statements do not include all the notes in the annual financial statements and, therefore, should be read in conjunction with the financial statements and combined notes thereto for the year ended December 31, 2025, in the Annual Report on Form 10-K. The accompanying unaudited financial statements include all normal recurring adjustments and others that, in the opinion of management, are necessary to present fairly the interim financial statements.

The preparation of financial statements in conformity with accounting principles generally accepted in the United States requires management to make estimates and assumptions that affect the amounts reported in the financial statements and accompanying combined notes. Actual results could differ from those estimates.

Management believes that the carrying value of certain of Williams’ property, plant, and equipment and intangible assets, notably certain assets acquired by Williams accounted for as business combinations between 2012 and 2014, may be in excess of current fair value. However, the carrying value of these assets, in management’s judgment, continues to be recoverable. It is reasonably possible that future strategic decisions, including transactions such as monetizing assets or contributing assets to new ventures with third parties, as well as unfavorable changes in

expected producer activities, could impact management’s assumptions and ultimately result in impairments of these assets. Such transactions or developments may also indicate that certain Williams’ equity-method investments have experienced other-than-temporary declines in value, which could result in impairment.

In November 2024, the Financial Accounting Standards Board (FASB) issued Accounting Standards Update (ASU) 2024-03, Income Statement - Reporting Comprehensive Income - Expense Disaggregation Disclosures, which requires public entities to disclose additional information in the notes to financial statements for certain types of expenses (including purchases of inventory, employee compensation, depreciation, amortization, and depletion) in commonly presented expense captions (such as cost of sales or general and administrative expenses). The amendments are effective for fiscal years beginning after December 15, 2026, and interim periods within those fiscal years beginning after December 15, 2027, with early adoption permitted. The impact of this standard is currently being evaluated.

In May 2026, the FASB issued ASU 2026-02, Environmental Credits and Environmental Credit Obligations, which establishes guidance for the recognition, measurement, presentation, and disclosure of environmental credits and related obligations. The amendments are effective for fiscal years beginning after December 15, 2027, and interim periods within those fiscal years, with early adoption permitted. The impact of this standard is currently being evaluated and is expected to primarily relate to NWP's compliance with the Washington State Climate Commitment Act.