2 Safe Harbor Statement This presentation contains statements which, to the extent they are not statements of historical or present fact, constitute “forward-looking statements” under the securities laws. These forward-looking statements are intended to provide management’s current expectations or plans for our future operating and financial performance, business prospects, outcomes of regulatory proceedings, market conditions, and other matters, based on what we believe to be reasonable assumptions and on information currently available to us. Forward-looking statements can be identified by the use of words such as “believe,” “expect,” “expectations,” “plans,” “strategy,” “prospects,” “estimate,” “project,” “target,” “anticipate,” “will,” “would,” “could,” “should,” “see,” “guidance,” “outlook,” “confident,” “may,” “continue,” “intend,” “goal,” “potential,” and other words of similar meaning. The absence of such words, expressions or statements, however, does not mean that the statements are not forward-looking. In particular, express or implied statements relating to future earnings, cash flow, results of operations, uses of cash, tax rates and other measures of financial performance, future actions, conditions or events, potential future plans, strategies or transactions of DT Midstream, and other statements that are not historical facts, are forward-looking statements. Forward-looking statements are not guarantees of future results and conditions, but rather are subject to numerous assumptions, risks, and uncertainties that may cause actual future results to be materially different from those contemplated, projected, estimated, or budgeted. Many factors may impact forward-looking statements of DT Midstream including, but not limited to, the following: changes in general economic conditions, including increases in interest rates and associated Federal Reserve policies, a potential economic recession, and the impact of inflation on our business; industry changes, including the impact of consolidations, alternative energy sources, technological advances, infrastructure constraints and changes in competition; changes in global trade policies and tariffs; global and domestic supply chain disruptions; actions taken by third-party operators, producers, processors, transporters and gatherers; changes in expected production from Expand Energy and other third parties in our areas of operation; demand for natural gas gathering, transmission, storage, transportation, sand mining, and water services; the availability and price of natural gas to the consumer compared to the price of alternative and competing fuels; our ability to successfully and timely implement our business plan; our ability to complete organic growth projects on time and on budget; our ability to finance, complete, or successfully integrate acquisitions; our ability to realize the anticipated benefits from acquisitions and our ability to manage the risks associated with acquisition activity; the price and availability of debt and equity financing; restrictions in our existing and any future credit facilities and indentures; the effectiveness of our information technology and operational technology systems and practices to detect and defend against evolving cyber attacks on United States critical infrastructure; changing laws regarding cybersecurity and data privacy, and any cybersecurity threat or event; operating hazards, environmental risks, and other risks incidental to gathering, storing and transporting natural gas; geologic and reservoir risks and considerations; natural disasters, adverse weather conditions, casualty losses and other matters beyond our control; the impact of outbreaks of illnesses, epidemics and pandemics, and any related economic effects; the impacts of geopolitical events, including the conflicts in Ukraine and the Middle East; labor relations and markets, including the ability to attract, hire and retain key employee and contract personnel; large customer defaults; changes in tax status, as well as changes in tax rates and regulations; the effects and associated cost of compliance with existing and future laws and governmental regulations, such as the Inflation Reduction Act and the One Big Beautiful Bill Act; changes in environmental laws, regulations or enforcement policies, including laws and regulations relating to pipeline safety, climate change and greenhouse gas emissions; changes in laws and regulations or enforcement policies, including those relating to construction and operation of new interstate gas pipelines, ratemaking to which our pipelines may be subject, or other non-environmental laws and regulations; our ability to qualify for federal income tax credits; our ability to develop low carbon business opportunities and deploy greenhouse gas reducing technologies; changes in insurance markets impacting costs and the level and types of coverage available; the timing and extent of changes in commodity prices; the success of our risk management strategies; the suspension, reduction or termination of our customers’ obligations under our commercial agreements; disruptions due to equipment interruption or failure at our facilities, or third-party facilities on which our business is dependent; the effects of future litigation; and the risks described in our Annual Report on Form 10-K for the year ended December 31, 2025 and our reports and registration statements filed from time to time with the SEC. The above list of factors is not exhaustive. New factors emerge from time to time. We cannot predict what factors may arise or how such factors may cause actual results to vary materially from those stated in forward-looking statements, see the discussion under the section entitled “Risk Factors” in our Annual Report for the year ended December 31, 2025, filed with the SEC on Form 10-K and any other reports filed with the SEC. Given the uncertainties and risk factors that could cause our actual results to differ materially from those contained in any forward-looking statement, you should not place undue reliance on any forward-looking statements. Any forward-looking statements speak only as of the date on which such statements are made. We are under no obligation to, and expressly disclaim any obligation to, update or alter our forward-looking statements, whether as a result of new information, subsequent events or otherwise.

Definition and reconciliation of Adjusted EBITDA (non-GAAP) to net income included in the appendix From prior year Adjusted EBITDA original guidance midpoint Final Investment Decision Third Quarter 2026 Accomplishments Solid financial performance Third quarter 2026 net income of $118 million and Adjusted EBITDA1 of $301 million Raising 2026 Adjusted EBITDA guidance midpoint and narrowing range to $1,185 - $1,225 million; updated midpoint represents 7% year-over-year growth2 Reaffirming 2027 Adjusted EBITDA early outlook of $1,225 - $1,295 million Executing new organic growth opportunities Advanced over $0.4 billion of new organic projects to FID3, increasing the total committed backlog to 70% Reached FID on Midwestern pipeline “MIST S1” mainline expansion of ~300 MMcf/d Reached FID on pipeline lateral off Midwestern to serve new 900 MW power plant in Indiana Reached FID on Guardian Phase 2 Modernization Advancing construction projects Received FERC approval for Guardian’s rate case settlement, which recovers Guardian Phase 1 modernization investment Guardian “G3” pipeline expansion remains on track, with the FERC certificate order scheduled for 1H 2027 3

Leading Organic Growth $3.4B project backlog DTM Provides a Distinctive Investment Opportunity Premium, high-quality, pure play natural gas attributes compared to peers High-Quality Portfolio Mix ~70% Pipeline segment Premier Geographic Presence Growing power and LNG demand Durable Contracting ~95% demand-based contracts1, ~8-year average2 contract tenor Represents % of 2025 revenue contribution comprised of demand, Minimum Volume Commitments (MVCs) or flowing gas/proved developed producing reserves Overall portfolio weighted average contract tenor as of 12/31/2025 DTM 2025 dividend based on annualized Q1 2025 Board-approved dividend ($0.82/share); DTM 2021-2025 Adjusted EBITDA CAGR based on 2021 original guidance to 2025 actual Peer average of gas-focused peers (WMB, KMI, AM, TRP, ENB) Definition and reconciliation of Adjusted EBITDA (non-GAAP) to net income included in the appendix Represents 2025 Pipeline and Gathering segment Adjusted EBITDA contributions Peer average includes WMB, KMI, TRP, ENB; Source: Peer company filings as of 2/13/2026 Investment Grade 2.8x on-balance sheet / 3.4x proportional 2026E YE leverage DTM3 Gas-Focused Peers 4 8% 2% Adjusted EBITDA5 CAGR 2021-2025 Dividend CAGR 2021-2025 Differentiated Business Mix and Backlog Business Mix as % of 2025 EBITDA6 Pipeline Gathering 70% 4 30% Peer-leading Dividend and Adjusted EBITDA Growth DTM Peer Average7 300% 260% Project Backlog as % of 2025 EBITDA DTM3 Gas-Focused Peers 4 12% 6% Backlog 75% Pipeline Projects

Represents 2026-2030 probability-weighted capex 5 Executing on ~$3.4 billion Organic Project Backlog over 2026-2030 Reached FID on ~70% of project backlog with $0.8 billion committed in nine months ~50% Reached FID 50% Pre-FID ~$3.4 billion Capital Project Backlog ~$2.4 billion total committed ~$0.4 billion committed in Q3 2026 >80% of total commitments in pipeline segment 1 Projects at 5-8x build multiples 70% Reached FID 30% Actively Advancing

1. Includes Allowance for Funds Used During Construction (AFUDC) Reached FID on Midwestern MIST S1 Expansion and New Lateral MIST S1 Mainline Expansion ~300 MMcf/d expansion with expected Q4 2029 in-service date Expansion will be completed via a combination of compression and looping Anchored by precedent agreements with investment-grade utilities 20-year contract terms Negotiated rates Power Plant Lateral Pipeline lateral serving new 900 MW power plant in Indiana 1H 2028 expected lateral pipeline in-service date Supported by 20-year, demand-based contract with a utility offtaker ~300 MMcf/d “MIST S1” Serving incremental power generation demand in southern Indiana 6 Pre-FID $275 to $325 million combined capital investment1 at ~5.5-6.5x build multiple New 900 MW Power Plant

7 Guardian Phase 2 Modernization Reaches FID Continuing investment in modernization projects to enhance system efficiency and reliability Disciplined investment supports long-term pipeline performance Capital investment will be recovered in pipeline rate cases Received FERC approval for Guardian’s rate case settlement, which recovers Guardian Phase 1 modernization investment Project Capital investment Expected in service Guardian Phase 1 $130 - $150M 2H 2027 Midwestern Phase 1 $140 - $160M 1H 2028 Viking Phase 1 $140 - $160M Q4 2028 Guardian Phase 2 $130 - $150M Q3 2030

Ramapo Enhancement Project 8 Expansion Projects Across Our Footprint Integrated network positioned to serve growing natural gas demand Expansion Project Target ISD Current Status Millennium R2R Q1 2027 In Execution Viking Pipeline expansion Q4 2027 In Execution Appalachia Gathering System expansion Q4 2027 In Execution Haynesville System expansion 2H 2028 In Execution Guardian Pipeline “G3” expansion Q4 2028 In Execution Vector 2028 Pipeline expansion Q4 2028 In Execution Midwestern “MIST S1” expansion Q4 2029 In Execution Millennium Pipeline “REP”1 Q4 2028 Open Season Closes 11/13 Midwestern “MIST” additional expansion phases As early as 2030 Active Customer Discussions Vector 2030 Pipeline expansion As early as Q4 2030 Negotiating Binding PAs Guardian Pipeline “G4” expansion 2031+ Evaluating Market Interest Millennium Pipeline expansion 2030+ Evaluating Market Interest Haynesville System expansion TBD Evaluating Market Interest NEXUS Pipeline expansion TBD Evaluating Market Interest Storage development/expansion TBD Evaluating Market Interest In Execution Pre-FID A B C D E F G H I A B E F G J L N K C J K D L M I H N O O M

Definition and reconciliation of Adjusted EBITDA (non-GAAP) to net income included in the appendix 9 Third Quarter 2026 Financial Results Q2 2026 Q3 2026 $305 $301 Pipeline Gathering Pipeline Higher revenue on joint venture pipelines Gathering Lower Northeast volumes 67% 33% xx Adjusted EBITDA1 (millions) segment % of total 66% 34%

Definition and reconciliation of Adjusted EBITDA (non-GAAP) to net income included in the appendix Definition and reconciliation of Operating Earnings and Operating Earnings per Share (non-GAAP) to reported earnings included in the appendix; EPS calculation based on average share count of approximately 103 million shares outstanding - diluted Definition and reconciliation of Distributable Cash Flow (non-GAAP) to net income included in the appendix Includes contribution to equity method investees 10 Guidance Updates Reflect Strong Year-to-Date Performance Raising 2026 Adjusted EBITDA and Distributable Cash Flow guidance (millions, except EPS) Prior Guidance Updated Guidance 2026 Adjusted EBITDA1 $1,155 - $1,225 $1,185 - $1,225 2026 Operating Earnings2 $455 - $495 $460 - $490 2026 Operating EPS2 $4.42 - $4.82 $4.47 - $4.77 2026 Distributable Cash Flow3 $830 - $890 $860 - $890 2026 Capital Investment4 $490 - $570 $450 - $510 Growth Capital $420 - $480 $375 - $425 Maintenance Capital $70 - $90 $75 - $85 2027 Adjusted EBITDA (early outlook) $1,225 - $1,295 $1,225 - $1,295

2026 guidance 2027 $375 - $425 11 2026 Capital Plan is Committed and 2027 is Advancing Capital efficiency lowering 2026 Growth Capital guidance by over 10% Growth capex (millions) Organic, demand-driven, capital investments Increasing 2027 committed capital to reflect new investments Total committed investments of ~$1.0 billion over 2026 and 2027 ~$2.4 billion of projects have reached FID through 2030 Committed New Commitments Pre-FID ~$400 Committed ~$610 Committed

Definition and reconciliation of Adjusted EBITDA (non-GAAP) to net income included in the appendix Definition and reconciliation of Operating Earnings and Operating Earnings per Share (non-GAAP) to reported earnings included in the appendix; EPS calculation based on average share count of approximately 103 million shares outstanding – diluted on September 30, 2026 and June 30, 2026 Definition and reconciliation of Distributable Cash Flow (non-GAAP) included in the appendix Includes contribution to equity method investees and excludes equity AFUDC 12 Quarterly Financial Results Three months ended (millions, except EPS) September 30, 2026 June 30, 2026 Key drivers Adjusted EBITDA1 $301 $305 Pipeline segment $202 $200 Higher revenue on joint venture pipelines Gathering segment $99 $105 Lower Northeast volumes in Q3 Operating Earnings2 $118 $112 Higher one-time income tax expense in Q2 Operating EPS2 $1.16 $1.09 Distributable Cash Flow3 $270 $174 Cash interest expense in Q2 Growth Capital4 $79 $86 Maintenance Capital $19 $24

13 Appendix

14 Gathering Volume Summary Strong year-over-year volume growth across Haynesville and Appalachia in Q3 Q3 2025 Q4 2025 Q1 2026 Q2 2026 Q3 2026 +6% Haynesville throughput Q3 2025 Q4 2025 Q1 2026 Q2 2026 Q3 2026 1.09 1.28 1.42 1.38 1.25 +15% Northeast throughput Appalachia Gathering Susquehanna Gathering Tioga Gathering Ohio Utica Gathering Blue Union Gathering (bcf/d) Producer curtailments driving lower expected volumes for Q4 2026 compared to Q3 2026

Key Growth Investment Projects in Progress Continuing track record of completing growth investments on time and on budget In progress project updates Reached FID on MIST S1, Midwestern power plant lateral, and Guardian Phase 2 Modernization Received FERC approval for Guardian’s rate case settlement, which recovers Guardian Phase 1 modernization investment Guardian “G3” FERC certificate order scheduled for 1H 2027 All other projects remain on schedule and on budget Projects in Execution1 Expected in-service dates Millennium Pipeline R2R Q1 2027 Guardian Pipeline Phase 1 Modernization 2H 2027 Viking Gas Transmission expansion Q4 2027 Appalachia Gathering System expansion Q4 2027 Midwestern Gas Transmission Phase 1 Modernization 1H 2028 Midwestern Gas Transmission power plant lateral – New 1H 2028 LEAP Phase 5 expansion 2H 2028 Viking Gas Transmission Phase 1 Modernization Q4 2028 Guardian Pipeline “G3” expansion Q4 2028 Vector Pipeline 2028 expansion Q4 2028 Midwestern Gas Transmission “MIST S1” expansion – New Q4 2029 Guardian Pipeline Phase 2 Modernization – New Q3 2030 15 1. Key growth projects that have reached FID

16 Executing Haynesville System Expansion Premier supply optionality and Gulf Coast market access drive continued expansions LEAP capacity (Bcf/d) Current Phase 5 expansion Total Expansion potential 0.2 2.3 Increasing Haynesville System supply access Long-term agreements with two producers Incremental East Texas connectivity in Carthage area expands access to growing producer activity LEAP Phase 5 expansion increases total capacity to 2.3 Bcf/d 200 MMcf/d expansion with expected 2H 2028 in-service date Project entails incremental compression and looping Underpinned by long-term, demand-based contract LEAP can be further expanded to ~4 Bcf/d to serve growing Gulf Coast LNG and industrial corridor demand ~4 +200 MMcf/d LEAP Phase 5 Expansion LNG Corridor Carthage Hub DTM assets DTM treating plants LNG facilities Electric compression Operational Under development Acreage dedication

Source: S&P Global Short-term Outlook – September 2026 17 Strong U.S. Demand and Production Fundamentals Over half of demand growth will be served by Haynesville and Appalachia production U.S. Natural Gas Demand Forecast 2025 2030 50 65 +15 bcf/d Production Forecast – DTM Basins (bcf/d) Haynesville Appalachia (bcf/d) 2025 2030 113 139 +26 bcf/d ResComm Industrial Power LNG Exports Mexican Exports Other

Assumes 1 GW = 0.15 Bcf/d natural gas demand Midcontinent Independent System Operator, Inc. PJM Interconnection LLC, RTO Region Source: Utility company announcements, S&P Global Commodity Insights North American Power Market Outlook, May 2026 18 Extensive Interstate Network Adjacent to Growing Utility Demand Data center opportunities accelerating Upper Midwest and Northeast natural gas demand 16 GW 11 GW 12 GW Utility Announced Data Center & Large Load Opportunities 10 GW ~50 GW Utility Announced Opportunities ~7.5 Bcf/d Natural Gas Demand1 Forecasted Total Annual Power Demand (TWh) 2025 2030 +20% 2025 2030 +22% MISO2 PJM3

Includes Illinois, Indiana, Kentucky, Michigan, Minnesota, Ohio, Tennessee and Wisconsin Assumes 1 GW = 0.15 Bcf/d of natural gas Source: S&P Global Commodity Insights US Coal-Fired Power Retirement Announcement – June 21, 2026 19 Strategically Located Assets to Serve Power Demand Growth Coal retirements will drive growth in natural gas demand 35 GW summer capacity Forecasted Coal Plant Retirements1 2026-2040 +5 Bcf/d Potential Natural Gas Demand2

Includes 0.25 Bcf/d receipt connectivity upon Haynesville system expansion in-service Interconnect provides a pathway to reach majority of terminals within the LNG corridor Source: Wood Mackenzie Strategic Planning Outlook – April 2026 20 Leading Market Position in the Haynesville Superior connectivity to basin supply and LNG markets provides competitive advantage 2025 2026 2027 2028 2029 2030 2031 2032 2033 2034 2035 +13 Bcf/d Haynesville Supply Forecast (Bcf/d) 2025 2026 2027 2028 2029 2030 2031 2032 2033 2034 2035 +15 Bcf/d DTM’s Haynesville System Direct LNG Market Connections (Bcf/d) Sabine Pass Cameron Calcasieu Pass Plaquemines Golden Pass Port Arthur Woodside Louisiana Existing/Future LEAP Interconnect Capacity (Bcf/d) LNG terminal / market Transco 0.5 Industrial / LNG corridor2 Cameron 0.25 Cameron LNG, Port Arthur LNG Creole Trail 1.0 Sabine Pass LNG Texas Eastern 0.75 Calcasieu Pass LNG Targa 0.1 Industrial TC Energy Gillis Access 1.0 Industrial / Plaquemines LNG, Calcasieu Pass LNG Cameron Expansion 0.25 Cameron LNG, Port Arthur LNG Driftwood Line 200 (Future) 1.0 Louisiana LNG ~4.9 Bcf/d Downstream Interconnectivity ~3.75 Bcf/d Receipt Capacity1

21 Non-GAAP Definitions Adjusted EBITDA and Distributable Cash Flow (DCF) are non-GAAP measures Adjusted EBITDA is defined as GAAP net income attributable to DT Midstream before expenses for interest, taxes, depreciation and amortization, and gains or losses from financing activities, further adjusted to include our proportional share of net income from our equity method investees (excluding interest, taxes, depreciation and amortization), and to exclude certain items we consider non-routine. We believe Adjusted EBITDA is useful to us and external users of our financial statements in understanding our operating results and the ongoing performance of our underlying business because it allows our management and investors to have a better understanding of our actual operating performance unaffected by the impact of interest, taxes, depreciation, amortization and non-routine charges noted in the table below. We believe the presentation of Adjusted EBITDA is meaningful to investors because it is frequently used by analysts, investors and other interested parties in our industry to evaluate a company’s operating performance without regard to items excluded from the calculation of such measure, which can vary substantially from company to company depending on accounting methods, book value of assets, capital structure and the method by which assets were acquired, among other factors. We use Adjusted EBITDA to assess our performance by reportable segment and as a basis for strategic planning and forecasting. Distributable Cash Flow (DCF) is calculated by deducting earnings from equity method investees, depreciation and amortization attributable to noncontrolling interests, cash interest expense, maintenance capital investment (as defined below), and cash taxes from, and adding interest expense, income tax expense, depreciation and amortization, and dividends and distributions from equity method investees to, Net Income Attributable to DT Midstream, further adjusted for certain items we consider non-routine and other non-cash items. Maintenance capital investment is defined as the total capital expenditures used to maintain or preserve assets or fulfill contractual obligations that do not generate incremental earnings. We believe DCF is a meaningful performance measurement because it is useful to us and external users of our financial statements in estimating the ability of our assets to generate cash earnings after servicing our debt, paying cash taxes and making maintenance capital investments, which could be used for discretionary purposes such as common stock dividends, retirement of debt or expansion capital expenditures. Adjusted EBITDA and DCF are not measures calculated in accordance with GAAP and should be viewed as a supplement to and not a substitute for the results of operations presented in accordance with GAAP. There are significant limitations to using Adjusted EBITDA and DCF as a measure of performance, including the inability to analyze the effect of certain recurring and non-recurring items that materially affect our net income or loss. Additionally, because Adjusted EBITDA and DCF exclude some, but not all, items that affect net income and are defined differently by different companies in our industry, Adjusted EBITDA and DCF do not intend to represent net income attributable to DT Midstream, the most comparable GAAP measure, as an indicator of operating performance and are not necessarily comparable to similarly titled measures reported by other companies. Reconciliation of net income attributable to DT Midstream to Adjusted EBITDA or DCF as projected for full-year 2026 or 2027 is not provided. We do not forecast net income as we cannot, without unreasonable efforts, estimate or predict with certainty the components of net income. These components, net of tax, may include, but are not limited to, impairments of assets and other charges, divestiture costs, acquisition costs, or changes in accounting principles. All of these components could significantly impact such financial measures. At this time, management is not able to estimate the aggregate impact, if any, of these items on future period reported earnings. Accordingly, we are not able to provide a corresponding GAAP equivalent for Adjusted EBITDA or DCF.

22 Non-GAAP Definitions Operating Earnings and Operating Earnings per share are non-GAAP measures Use of Operating Earnings Information – Operating Earnings exclude non-recurring items, certain mark-to-market adjustments and discontinued operations. DT Midstream management believes that Operating Earnings provide a more meaningful representation of the company’s earnings from ongoing operations and uses Operating Earnings as the primary performance measurement for external communications with analysts and investors. Internally, DT Midstream uses Operating Earnings to measure performance against budget and to report to the Board of Directors. In this presentation, DT Midstream provides guidance for future period Operating Earnings. It is likely that certain items that impact the company’s future period reported results will be excluded from operating results. A reconciliation to the comparable future period reported earnings is not provided because it is not possible to provide a reliable forecast of specific line items (i.e., future non-recurring items, certain mark-to-market adjustments and discontinued operations). These items may fluctuate significantly from period to period and may have a significant impact on reported earnings.

New slide 23 Non-GAAP Reconciliations Reconciliation of Reported to Operating Earnings – DT Midstream Consolidated Three Months Ended September 30, June 30, 2026 2026 Reported Earnings Pre-tax Adjustments Income Taxes (1) Operating Earnings Reported Earnings Pre-tax Adjustments Income Taxes (1) Operating Earnings (millions) Adjustments $ — $ — $ — $ — Net Income Attributable to DT Midstream $ 118 $ — $ — $ 118 $ 112 $ — $ — $ 112 Nine Months Ended September 30, September 30, 2026 2025 Reported Earnings Pre-tax Adjustments Income Taxes (1) Operating Earnings Reported Earnings Pre-tax Adjustments Income Taxes (1) Operating Earnings (millions) Adjustments — — — — Net Income Attributable to DT Midstream $ 360 $ — $ — $ 360 $ 330 $ — $ — $ 330 (1) Excluding tax related adjustments, the amount of income taxes was calculated based on a combined federal and state income tax rate, considering the applicable jurisdictions of the respective segments and deductibility of specific operating adjustments

Non-GAAP Reconciliations Reconciliation of Reported to Operating Earnings per diluted share(1) – DT Midstream Consolidated 24 Nine Months Ended September 30, September 30, 2026 2025 Reported Earnings Pre-tax Adjustments Income Taxes (2) Operating Earnings Reported Earnings Pre-tax Adjustments Income Taxes (2) Operating Earnings (per share) Adjustments — — — — Net Income Attributable to DT Midstream $ 3.51 $ — $ — $ 3.51 $ 3.22 $ — $ — $ 3.22 (1) Per share amounts are divided by Weighted Average Common Shares Outstanding — Diluted, as noted on the Consolidated Statements of Operations (2) Excluding tax related adjustments, the amount of income taxes was calculated based on a combined federal and state income tax rate, considering the applicable jurisdictions of the respective segments and deductibility of specific operating adjustments Three Months Ended September 30, June 30, 2026 2026 Reported Earnings Pre-tax Adjustments Income Taxes (2) Operating Earnings Reported Earnings Pre-tax Adjustments Income Taxes (2) Operating Earnings (per share) Adjustments $ — $ — $ — $ — Net Income Attributable to DT Midstream $ 1.16 $ — $ — $ 1.16 $ 1.09 $ — $ — $ 1.09

25 Reconciliation of Net Income Attributable to DT Midstream to Adjusted EBITDA Non-GAAP Reconciliations Three Months Ended Nine Months Ended September 30, June 30, September 30, September 30, 2026 2026 2026 2025 Consolidated (millions) Net Income Attributable to DT Midstream $ 118 $ 112 $ 360 $ 330 Plus: Interest expense 40 42 122 120 Plus: Income tax expense 41 53 130 104 Plus: Depreciation and amortization 71 68 208 191 Plus: EBITDA from equity method investees (1) 69 66 213 206 Less: Gain from financing activities (1) (1) (2) — Less: Interest income (2) (1) (4) (2) Less: Earnings from equity method investees (34) (33) (110) (101) Less: Depreciation and amortization attributable to noncontrolling interests (1) (1) (3) (3) Adjusted EBITDA $ 301 $ 305 $ 914 $ 845 (1) Includes share of our equity method investees’ earnings before interest, taxes, depreciation and amortization, which we refer to as “EBITDA.” A reconciliation of earnings from equity method investees to EBITDA from equity method investees follows: Three Months Ended Nine Months Ended September 30, June 30, September 30, September 30, 2026 2026 2026 2025 (millions) Earnings from equity method investees $ 34 $ 33 $ 110 $ 101 Plus: Depreciation and amortization attributable to equity method investees 22 20 63 63 Plus: Interest expense attributable to equity method investees 13 13 40 42 EBITDA from equity method investees $ 69 $ 66 $ 213 $ 206

26 Reconciliation of Net Income Attributable to DT Midstream to Adjusted EBITDA Pipeline Segment Non-GAAP Reconciliations Three Months Ended Nine Months Ended September 30, June 30, September 30, September 30, 2026 2026 2026 2025 Pipeline (millions) Net Income Attributable to DT Midstream $ 93 $ 86 $ 287 $ 277 Plus: Interest expense 14 14 42 38 Plus: Income tax expense 33 41 104 87 Plus: Depreciation and amortization 29 28 86 83 Plus: EBITDA from equity method investees (1) 69 66 213 206 Less: Gain from financing activities — (1) (1) — Less: Interest income (1) — (2) (1) Less: Earnings from equity method investees (34) (33) (110) (101) Less: Depreciation and amortization attributable to noncontrolling interests (1) (1) (3) (3) Adjusted EBITDA $ 202 $ 200 $ 616 $ 586 (1) Includes share of our equity method investees’ earnings before interest, taxes, depreciation and amortization, which we refer to as “EBITDA.” A reconciliation of earnings from equity method investees to EBITDA from equity method investees follows: Three Months Ended Nine Months Ended September 30, June 30, September 30, September 30, 2026 2026 2026 2025 (millions) Earnings from equity method investees $ 34 $ 33 $ 110 $ 101 Plus: Depreciation and amortization attributable to equity method investees 22 20 63 63 Plus: Interest expense attributable to equity method investees 13 13 40 42 EBITDA from equity method investees $ 69 $ 66 $ 213 $ 206

27 Reconciliation of Net Income Attributable to DT Midstream to Adjusted EBITDA Gathering Segment Non-GAAP Reconciliations Three Months Ended Nine Months Ended September 30, June 30, September 30, September 30, 2026 2026 2026 2025 Gathering (millions) Net Income Attributable to DT Midstream $ 25 $ 26 $ 73 $ 53 Plus: Interest expense 26 28 80 82 Plus: Income tax expense 8 12 26 17 Plus: Depreciation and amortization 42 40 122 108 Less: Gain from financing activities (1) — (1) — Less: Interest income (1) (1) (2) (1) Adjusted EBITDA $ 99 $ 105 $ 298 $ 259

Non-GAAP Reconciliations 28 Reconciliation of Net Income Attributable to DT Midstream to Distributable Cash Flow Three Months Ended Nine Months Ended September 30, June 30, September 30, September 30, 2026 2026 2026 2025 Consolidated (millions) Net Income Attributable to DT Midstream $ 118 $ 112 $ 360 $ 330 Plus: Interest expense 40 42 122 120 Plus: Income tax expense 41 53 130 104 Plus: Depreciation and amortization 71 68 208 191 Less: Gain from financing activities (1) (1) (2) — Less: Earnings from equity method investees (34) (33) (110) (101) Less: Depreciation and amortization attributable to noncontrolling interests (1) (1) (3) (3) Plus: Dividends and distributions from equity method investees 64 40 160 139 Less: Cash interest expense (2) (77) (79) (75) Less: Cash taxes (4) (3) (9) (3) Less: Maintenance capital investment (1) (19) (24) (54) (33) Less: Other non-cash adjustments (3) (2) (5) — Distributable Cash Flow $ 270 $ 174 $ 718 $ 669 (1) Maintenance capital investment is defined as the total capital expenditures used to maintain or preserve assets or fulfill contractual obligations that do not generate incremental earnings.