NORTHWEST PIPELINE LLC

Williams’ Consolidated Overview

The following table and discussion is a summary of Williams’ consolidated results of operations for the three months ended March 31, 2026, compared to the three months ended March 31, 2025, and should be read in conjunction with the results of operations by segment, as discussed in further detail following this consolidated overview discussion.

•Higher revenues associated with expansion projects at the Transmission, Power & Gulf and the West segments;

•Increased Transco transportation and storage rates and Gulf Coast Storage rates at the Transmission, Power & Gulf segment.

The net sum of Product sales and service revenues – commodity consideration, Product costs and net processing commodity expenses, and net realized gains and losses on commodity derivatives related to sales of product and shrink gas purchases for processing plants for the reportable segments comprise Commodity Margins. Service revenues - commodity consideration represent payments received in the form of commodities for processing services provided. Most of these commodity volumes are sold during the month processed and are offset within Product costs and net processing commodity expenses. The sum of Product sales and net realized gains and losses on commodity derivatives related to the upstream operations comprise Net realized product sales.

The Product sales and service revenues – commodity consideration increase primarily consists of:

•Higher marketing sales activities primarily related to higher net gas marketing sales activities, partially offset by lower NGL marketing sales activities at the Gas & NGL Marketing Services segment; partially offset by

•Lower product sales from upstream operations primarily related to lower volumes, including the first quarter 2026 sale of interests in certain upstream ventures in the South Mansfield area of the Haynesville Shale region (See Note 3 – Divestitures), at Other.

As Williams is acting as agent for natural gas marketing customers, its natural gas marketing product sales are presented net of the related costs of those activities within the Gas & NGL Marketing Services segment.

Net gain (loss) from commodity derivatives includes realized and unrealized gains and losses from derivative instruments reflected within Total revenues primarily in the Gas & NGL Marketing Services segment, as well as upstream operations at Other (see Note 9 – Commodity Derivatives).

Williams experiences significant earnings volatility from the fair value accounting required for the derivatives used to hedge a portion of the economic value of the underlying transportation and storage capacity portfolios as well as upstream-related production. However, the unrealized fair value measurement gains and losses on the derivatives are generally offset by valuation changes in the economic value of the underlying production or transportation and storage capacity contracts, which are not recognized until the underlying transaction occurs.

The Product costs and net processing commodity expenses decrease primarily consists of lower marketing activities related to NGLs at the Gas & NGL Marketing Services segment.

Operating and maintenance expenses increased primarily due to higher operating taxes.

Depreciation, depletion, and amortization expenses decreased primarily related to the sale of certain upstream ventures in the South Mansfield area of the Haynesville Shale region at Other, substantially offset by assets placed in service at the West segment.

Gain on sale of certain assets reflects a gain from the sale of certain upstream ventures in the South Mansfield area of the Haynesville Shale region in 2026, at Other.

Interest expense was primarily impacted by 2025 and 2026 debt issuances and retirements (see Note 7 – Debt and Banking Arrangements), partially offset by higher interest capitalized due to ongoing expansion projects.

Provision (benefit) for income taxes changed unfavorably primarily due to higher pre-tax income. See Note 6 – Provision (Benefit) for Income Taxes for a discussion of the effective tax rate compared to the federal statutory rate for both periods.

Period-Over-Period Operating Results – Williams’ Segments

Williams’ CODM evaluates segment operating performance based upon Modified EBITDA. Note 11 – Segment Disclosures includes a reconciliation of this non-GAAP measure to Income (loss) before income taxes. Management uses Modified EBITDA because it is an accepted financial indicator used by investors to compare company performance. In addition, management believes that this measure provides investors an enhanced perspective of the operating performance of Williams’ assets. Modified EBITDA should not be considered in isolation or as a substitute for a measure of performance prepared in accordance with GAAP.

(1)Included as a component of Commodity margins.

Transmission, Power & Gulf Modified EBITDA increased primarily due to higher Service revenues, partially offset by higher Other segment costs and expenses.

•A $68 million increase in Transco’s revenues primarily associated with expansion projects placed in service, notably Texas Louisiana Energy Pathway in April 2025, Southeast Energy Connector in April 2025, Commonwealth Energy Connector in November 2025, and Alabama Georgia Connector in October 2025; and transportation and storage rate increases;

•A $25 million increase in Gulf Coast Storage’s revenues primarily associated with higher park and loan services and higher storage rates;

•A $19 million increase in Discovery’s revenues primarily in natural gas gathering revenues due to volumes from the Shenandoah expansion project that went in-service in July 2025;

•A $13 million increase in the Western Gulf Coast region primarily due to higher natural gas gathering and crude oil transportation volumes from the Whale expansion project that went in-service in January 2025;

•A $10 million increase in the Eastern Gulf Coast region primarily due to higher crude oil transportation and natural gas gathering volumes from new wells at Blind Faith in the Ballymore field;

•An $8 million increase in NWP’s revenues primarily due to transportation rate increases.

Other segment costs and expenses increased primarily due to:

•Higher operating expenses and administrative costs including higher employee-related costs as well as increased corporate allocations and property taxes; partially offset by

•Favorable change in equity AFUDC primarily from Driftwood Pipeline’s Line 200 and other capital projects within the regulated businesses.

Northeast G&P

(1)Included as a component of Commodity margins.

Northeast G&P Modified EBITDA increased primarily due to higher Proportional Modified EBITDA of equity-method investments and higher Service revenues.

•A $16 million increase in revenues at the Northeast JV primarily related to higher transportation & fractionation volumes, higher gathering volumes, and higher processing rates;

•An $8 million increase in revenues associated with reimbursable expenses, which is offset by similar changes in the charges included in Other segment costs and expenses; partially offset by

•A $17 million decrease in gathering revenues at Susquehanna Supply Hub primarily related to lower volumes.

Proportional Modified EBITDA of equity-method investments increased at Appalachia Midstream Investments primarily driven by escalated gathering rates and higher gathering volumes.

West

(1) Included as a component of Commodity margins.

West Modified EBITDA increased primarily due to higher Service revenues, partially offset byhigher Other segment costs and expenses.

•A $54 million increase in the Haynesville Shale region primarily due to higher gathering volumes including those resulting from Louisiana Energy Gateway which was placed into service in third-quarter 2025 and the acquisition of Saber Midstream, LLC in June 2025;

•An $11 million increase in the DJ Basin region primarily due to higher gathering volumes, including those associated with the acquisition of natural gas gathering and processing assets from Rimrock Energy Partners, LLC on January 31, 2025; partially offset by

•A $10 million decrease in the Eagle Ford Shale region primarily due to lower MVC revenue.

Other segment costs and expenses increased primarily due to higher operating expenses, including operating taxes, associated with Louisiana Energy Gateway.

Gas & NGL Marketing Services

(1) Included as a component of Commodity margins.

Gas & NGL Marketing Services Modified EBITDA decreased primarily due to an unfavorable change in Net unrealized gain (loss) from commodity derivative instruments, partially offset by higher Commodity marginsand Proportional Modified EBITDA of equity-method investments.

Commodity margins increased $57 million primarily due to a $50 million increase in natural gas marketing margins, including $32 million of higher natural gas transportation capacity marketing margins and $18 million of higher natural gas storage marketing margins, both primarily driven by favorable net realized pricing spreads.

Net unrealized gain (loss) from commodity derivative instruments within Segment revenues and Net processing commodity expenses relates to derivative contracts that are not designated as hedges for accounting purposes. The change from 2025 is primarily due to a change in forward commodity prices relative to hedge positions in 2026 compared to 2025.

Proportional Modified EBITDA of equity-method investments increased driven by the investment in Cogentrix, which was purchased in March 2025.

Other

(1) Included as a component of Net realized product sales.

Modified EBITDA from upstream operations, corporate, and other business activities increased primarily due to:

•A $182 million Gain on sale of certain assets from the sale of certain South Mansfield upstream interests, which was completed in January 2026.

•A $15 million decrease in Net realized product sales from upstream operations driven by the sale of the South Mansfield interests.

•An increase of $6 million in Other costs and expenses primarily due to higher upstream operating expenses in the Wamsutter region, including of higher production expenses and higher ad valorem and production taxes both driven by increased volumes during 2026. These increases were partially offset by a decrease in upstream operating expenses associated with the sale South Mansfield interests.