#11000 PER 1000RRY 10:300 PER REV L AT A M POWERED BY LPC 900 BW MINDORO Fundamentally Focused Monthly Investor Presentation January 2024 AltaGas#2POWERED BY LPC 1000 PER EX BY MINDORO 130300 10 AltaGas LDPERC Forward-Looking Information This presentation contains forward-looking information (forward-looking statements). Words such as "may", "can", "would", "could", "should", "likely", "will", "intend", "contemplate", "plan", "anticipate", "believe", "aim", "seek", "future", "commit", "propose", "contemplate", "estimate", "focus", "strive", "forecast", "expect", "project", "target", "guarantee", "potential", "objective", "continue", "outlook", "guidance", "growth", "long-term", "vision", "opportunity" and similar expressions suggesting future events or future performance, as they relate to AltaGas Ltd. (AltaGas or the Corporation) or any affiliate of the Corporation, are intended to identify forward-looking statements. In particular, this presentation contains forward-looking statements with respect to, among other things, business objectives, strategy, expected growth, results of operations, performance, business projects and opportunities and financial results. Specifically, such forward-looking statements included in this document include, but are not limited to, statements with respect to the following: AltaGas' expectations and beliefs surrounding the energy evolution, including that natural gas will be critical in the energy transition globally; expectations regarding global population growth and increasing demand for energy; future demand for natural gas and LPG; expectations surrounding Asian propane and butane import needs; the expectation that Canadian propane and butane supply will increase materially; the expectation that global energy demand growth will rise 15% by 2050; the belief that balancing energy affordability, reliability and climate change is critical for long-term success; AltaGas' Midstream and Utilities ESG priorities; enterprise ESG goals for emissions, safety and diversity and inclusion; AltaGas' focus areas including equity self-funding model, commercial de-risking, continued de-leveraging, optimizing returns and capital allocation; AltaGas' intention to deliver on its core objectives; expectations regarding export volume growth post-REEF and delivering customers the best LPG netbacks under long-term tolling arrangements; expectations surrounding the integration of the Pipestone assets and expected benefits of the Pipestone acquisition; commercial de-risking; AltaGas' ability to strengthen the Midstream value chain; the expectation that Canadian LNG developments will create adjacent opportunities; projected WCSB LPG available for exports; projected RIPET tolling for forward indicative year, the expectation that AltaGas' structural shipping advantage will continue; the belief that AltaGas has robust growth opportunities in the global LPG market; projected global exports tolling agreements; the expectation that AltaGas will become the preeminent Midstream platform in Western Canada; expectations and near-term priorities for Rolling Hills and Pacific Northwest Hydrogen Hub; the expectation of full FEED for REEF with FID expected in H1/24; anticipated improved earnings, strong customer growth, continued network modernization, system extension opportunities and climate and energy efficiency initiatives driving better outcomes for all stakeholders in Utilities; the belief that electrification would increase emissions and cripple economic activity; AltaGas' commitment to building alliances with advocacy groups and working with governments to ensure stakeholders understand affordability, reliability, energy security and climate benefits of natural gas; expected benefits of improving returns at WGL and closing the ROE gap; accelerated replacement program spending through 2028; expectations surrounding the Prince William County landfill RNG interconnection; WGL and SEMCO's RNG advancements; anticipated material long-term opportunities for gas utilities resulting from climate focus; AltaGas' focus on multi-year growth trajectory across Utilities and Midstream, continued expansion, continued deleveraging with the goal of reaching 4.5x net debt/normalized EIBTDA, dividend growth and compounding shareholder value; AltaGas' financial roadmap; expectations regarding AltaĠas' investment capacity; AltaGas' capital allocation framework; the belief that selling MVP is the quickest path to accelerating deleveraging; AltaGas' path to achieving its leverage target; the belief that AltaGas will have additional financial flexibility once Pipestone II and REEF are online with further flexibility from asset optimization, organic growth, cost management and disciplined capital allocation; AltaGas' focus on de-risking through commercial frameworks; AltaGas' dividend policy and anticipated dividend growth; anticipated dividend payout through 2028; expected annual dividend CAGR through 2028; anticipated normalized EPS, normalized EBITDA and planned capital program; key 2024 budget assumptions; the expectation that AltaGas will achieve results in the upper half of the 2023 normalized EBITDA guidance range; anticipated 2024 normalized EBITDA and normalized EPS; the 2024 capital budget and expected allocations among Utilities, Midstream and Corporate/Power; quarterly normalized EBITDA by segment and on a consolidated basis; 2024 hedging philosophy; and expectations regarding normalized earnings, normalized EBITDA and net debt/normalized EBITDA through 2024. These statements involve known and unknown risks, uncertainties and other factors that may cause actual results, events and achievements to differ materially from those expressed or implied by such statements. Such statements reflect AltaGas' current expectations, estimates, and projections based on certain material factors and assumptions at the time the statement was made. Material assumptions include: anticipated timing of asset sale and acquisition closings; effective tax rates, U.S./Canadian dollar exchange rates; inflation; interest rates, credit ratings, regulatory approvals and policies; expected commodity supply, demand and pricing; volumes and rates; propane price differentials; degree day variance from normal; pension discount rate; financing initiatives; the performance of the businesses underlying each sector; impacts of the hedging program; weather; frac spread; access to capital; future operating and capital costs; timing and receipt of regulatory approvals; seasonality; planned and unplanned plant outages; timing of in-service dates of new projects and acquisition and divestiture activities; taxes; operational expenses; returns on investments; dividend levels; key 2024 budget assumptions and transaction costs. AltaGas' forward-looking statements are subject to certain risks and uncertainties which could cause results or events to differ from current expectations, including, without limitation: risks related to conflict in Eastern Europe; health and safety risks; operating risks; infrastructure; natural gas supply risks; volume throughput; service interruptions; transportation of petroleum products; market risk; inflation; general economic conditions; cyber security, information, and control systems; climate-related risks; environmental regulation risks; regulatory risks; litigation; changes in law; Indigenous and treaty rights; political uncertainty and civil unrest; decommissioning, abandonment and reclamation costs; reputation risk; weather data; capital market and liquidity risks; interest rates; internal credit risk; foreign exchange risk; debt financing, refinancing, and debt service risk; counterparty and supplier risk; technical systems and processes incidents; dependence on certain partners; growth strategy risk; construction and development; underinsured and uninsured losses; impact of competition in AltaGas' businesses; counterparty credit risk; composition risk; collateral; rep agreements; market value of common shares and other securities; variability of dividends; potential sales of additional shares; labor relations; key personnel; risk management costs and limitations; commitments associated with regulatory approvals for the acquisition of WGL; cost of providing retirement plan benefits; failure of service providers; risks related to pandemics, epidemics or disease outbreaks,; and the other factors discussed under the heading "Risk Factors" in the Corporation's Annual Information Form for the year ended December 31, 2022 and set out in AltaGas' other continuous disclosure documents. Many factors could cause AltaGas' or any particular business segment's actual results, performance or achievements to vary from those described in this presentation, including, without limitation, those listed above and the assumptions upon which they are based proving incorrect. These factors should not be construed as exhaustive. Should one or more of these risks or uncertainties materialize, or should assumptions underlying forward-looking statements prove incorrect, actual results may vary materially from those described in this presentation as intended, planned, anticipated, believed, sought, proposed, estimated, forecasted, expected, projected or targeted and such forward-looking statements included in this presentation, should not be unduly relied upon. The impact of any one assumption, risk, uncertainty, or other factor on a particular forward-looking statement cannot be determined with certainty because they are interdependent and AltaGas' future decisions and actions will depend on management's assessment of all information at the relevant time. Such statements speak only as of the date of this presentation. AltaGas does not intend, and does not assume any obligation, to update these forward-looking statements except as required by law. The forward-looking statements contained in this presentation are expressly qualified by these cautionary statements. Financial outlook information contained in this presentation about prospective financial performance, financial position, or cash flows is based on assumptions about future events, including economic conditions and proposed courses of action, based on AltaGas management's assessment of the relevant information currently available. Readers are cautioned that such financial outlook information contained in this presentation should not be used for purposes other than for which it is disclosed herein. Additional information relating to AltaGas, including its quarterly and annual MD&A and Consolidated Financial Statements, AIF, and press releases are available through AltaGas' website at www.altagas.ca or through SEDAR+ at www.sedarplus.ca. NON-GAAP MEASURES This presentation contains references to certain financial measures that do not have a standardized meaning prescribed by US GAAP and may not be comparable to similar measures presented by other entities. The non-GAAP measures and their reconciliation to US GAAP financial measures are shown in AltaGas' Management's Discussion and Analysis (MD&A) as at and for the period ended September 30, 2023. These non-GAAP measures provide additional information that management believes is meaningful regarding AltaGas' operational performance, liquidity and capacity to fund dividends, capital expenditures, and other investing activities. Readers are cautioned that these non-GAAP measures should not be construed as alternatives to other measures of financial performance calculated in accordance with US GAAP. EBITDA is a measure of AltaGas' operating profitability prior to how business activities are financed, assets are amortized, or earnings are taxed. EBITDA is calculated from the Consolidated Statements of Income (Loss) using net income (loss) adjusted for pre tax depreciation and amortization, interest expense, and income tax expense (recovery). Normalized EBITDA includes additional adjustments for transaction costs related to acquisitions and dispositions, unrealized losses (gains) on risk management contracts, gains on investments, gains on sale of assets, restructuring costs, dilution loss on equity investment, provisions (reversal of provisions) on assets, provisions on investments accounted for by the equity method, foreign exchange gains, and accretion expenses related to asset retirement obligations. AltaGas presents normalized EBITDA as a supplemental measure. Normalized EBITDA is used by Management to enhance the understanding of AltaGas' earnings over periods. The metric is frequently used by analysts and investors in the evaluation of entities within the industry as it excludes items that can vary substantially between entities depending on the accounting policies chosen, the book value of assets, and the capital structure. Normalized earnings per share (EPS) is calculated with reference to normalized net income divided by the average number of shares outstanding during the period. Normalized net income is calculated from the Consolidated Statements of Income (Loss) using net income (loss) applicable to common shares adjusted for transaction costs related to acquisitions and dispositions, unrealized losses (gains) on risk management contracts, non-controlling interest portion of non-GAAP adjustments, gains on investments, gains on sale of assets, provisions on assets, restructuring costs, dilution loss on equity investment and provisions on investments accounted for by the equity method. Normalized net income per share is used by Management to enhance the comparability of AltaGas' earnings, as these metrics reflect the underlying performance of AltaGas' business activities. Funds from operations is calculated from the Consolidated Statements of Cash Flows and is defined as cash from operations before net changes in operating assets and liabilities and expenditures incurred to settle asset retirement obligations. Net debt is used by the Corporation to monitor its capital structure and financing requirements. It is also used as a measure of the Corporation's overall financial strength and is presented to provide this perspective to analysts and investors. Net debt is defined as short-term debt (excluding third-party project financing obtained for the construction of certain energy management services projects), plus current and long-term portions of long-term debt, less cash and cash equivalents, and statutory tax rate change. Normalized net income (loss) is used by Management to enhance the comparability of AltaGas' earnings, as it reflects the underlying performance of AltaGas' business activities. 2#3A Strong Platform with Streamlined Asset Base AltaGas A leading energy infrastructure platform that invests in and operates long-life infrastructure assets that provide stable and growing value for our stakeholders. Everyday we are focused on connecting customers and markets in the most efficient manner possible. Wellhead Midstream GAS Gas Gathering & Processing Integrated Midstream Business - from wellhead to global markets Legend: 2.1 Bcf/d¹ Processing AltaGas Midstream Activities Third-Party NGLS NGL Extraction & Fractionation C3 & C4 Transportation, Storage & Rail Logistics C3 & C4 Export C3 & C4 Global Markets 65,000 Bbl/d² C5 000 000 6 Facilities: Sales: Local and U.S. Markets >6 MMBIs Storage, Truck and rail transloading; ~4,700 rail cars Fort Saskatchewan - Local Blending ~150,000 Bbl/d³ Export capability 2 Terminals: RIPET, Ferndale VLGC to Asia & Global Markets AltaGas ~2,800 ~512,000 1 Washington Gas (ALA-TSX) Employees customers Utilities ~550,000 2 ~$24B ~$7.7B customers MARYLAND Total Assets Market Cap4 3 ~165,000 customers VIRGINIA ~$18.2B EV4 60% Utilities 40% Midstream Regulated Gas Distribution: US$5.2B 4 ~320,000 customers Rate Base5 AltaGas SEMCOENERGY Retail Energy Marketing Sell natural gas and power directly to residential, commercial, and industrial customers DISTRICT OF ③COLUMBIA MICHIGAN Detroit Other Services Efficiency, Technology, Transportation and Generation 1. Based on ALA working interest capacity in FG&P and extraction, based on nameplate capacity 2. Based on ALA 100% working interest facilities and ALA % capacity in non-operated facilities, based on nameplate capacity 3. Includes RIPET and Ferndale 4. As of February 28, 2023 5. Prior to March 1, 2023, divestiture of the Alaska Utilities to TriSummit Utilities. See "Forward-looking Information" 3#4AltaGas Value Proposition Diversified, Low-Risk Business Model with Visible Growth and Disciplined Capital Allocation Low Risk Energy Infrastructure 1 2 3 Disciplined Capital Allocation Platform Providing Stable and Growing Earnings/Cash Flows Robust energy fundamentals for natural gas and NGLS Low-risk commercial frameworks - >80% utilities/take-or-pay and fee- for-service contracts >90% of earnings from Utilities / Investment Grade counterparties Diversified platform provides opportunity to optimize capital allocation Visible, Industry- Leading Growth Utilities modernization programs and customer growth provides visible and low-risk growth Growing global LPG demand provides structural growth tailwind Opportunities to fill latent capacity through lower-capex investments drive improving returns Energy evolution provides opportunities to augment growth Balance sheet de-risking - follow path to 4.5x net debt / normalized EBITDA Equity Self-funding model Prudent and sustainable dividend payout ratio (~50-60% of normalized EPS) Disciplined capital allocation Notes: 1) Non-GAAP measure; see discussion in the advisories. *See "Forward-looking Information" AltaGas Low Risk Commercial Model; Industry-Leading Growth 4#5Our Focus Areas Focus on growing, de-risking, and strengthening the enterprise. 1 Equity Self- funding Model Utilize an equity self-funding model to advance organic growth 2 Commercial De-risking ■ Increase take-or-pay contracting and tolling in Midstream ■ Pursue weather normalization / decoupling and other regulatory changes at Utilities in D.C. " 3 Continued De-leveraging Achieve 4.5x net debt / normalized EBITDA¹. Build dry powder 4 Optimize Returns Optimize assets for the strongest returns ■ Close remaining ROE gap at the Utilities ■ Brownfield optimization projects across the Midstream platform 5 Capital Allocation ■ Maintain prudent capital allocation that drives organic growth and supports dividend increases ■ Filter organic growth opportunities to the best risk adjusted returns ■ Maintain optionality around selective M&A, potential further leverage reduction, and/or stock buybacks, once leverage targets achieved Notes: 1) Non-GAAP measure; see discussion in the advisories. *See "Forward-looking Information". AltaGas 5#6Our Financial Roadmap 1 Leverage and optimize existing assets 2 3 Strengthen balance sheet Allocate capital to the best projects 4 Equity self- funding model Grow normalized EBITDA1 with no-to-low-capex investments Improve ROIC/ROE ■ Drive towards 4.5x or lower net debt/ normalized EBITDA¹ Build dry powder Non-core asset monetization Focus on projects that provide strong risk adjusted returns Sufficient internal investment capacity for organic growth Notes: 1) Non-GAAP measure; see discussion in the advisories. *See "Forward-looking Information". AltaGas Operating with Strong Financial Discipline and Living within Guardrails וס#7Low-Risk Energy Infrastructure Steady and Reliable Growth Low Risk Energy Infrastructure Platform Long-life infrastructure assets that provide durable and growing normalized EPS and FFO Investment Grade Credit Rating AltaGas Strong Commercial Constructs Commercial Contract Type² 4% Credit Ratings S&P Fitch Moody's BBB- (stable) 9% BBB (stable) BBB SEMCO (stable) A3 (stable) WGL Holdings BBB- (stable) BBB (stable) Washington Gas A- (stable) A- (stable) 15% 17% ■ Utilities ■ Take or Pay 55% ■ Fee for Service ■ Exports Commodity ~80% of 2024E normalized EBITDA³ from Utilities, take-or-pay or fee-for-service contracts Counterparty Credit Quality ~45% Midstream 1,3,4 Corporate/Other ~55% Utilities 1,3,4 Note: All ratings in the table above are Issuer Ratings On the path to 26% 4.5x 8% ■ Utilities & A ■ BBB 66% ■BB & Lower Net Debt/ Normalized EBITDA Notes: 1) 2024E normalized EBITDA; 2) Differential: Merchant unhedged Global Export; Commodity: Frac exposed volumes, hedged and unhedged. 3) Non-GAAP measure; see discussion in the advisories See "Forward-looking Information"; 4) Represents mid-point guidance; *See "Forward-looking information" AltaGas >90% of 2024E Normalized EBITDA³ expected from Utilities or investment grade counterparties 7#8Compounding Long-term Dividends at 5-7% CAGR DIVIDEND PHILOSOPHY ■ Plan to return capital through sustainable dividends increases Industry leading normalized EPS and FFO growth provides the opportunity to grow DPS at the same rate 1 2 50-60% Payout Ratio Target Calibrated at a Logical Portion of Normalized EPS Midstream Peers Utility Peers $1.19/Share 2024 Dividend Represents a 6% increase or a $0.07/share increase versus 2023. 5-7% Approximate Annual Dividend CAGR Range Expected Over the Next Five Years Long-term Implied Dividends Per Share Growth Rate Annual dividend growth rate adjustable up to AltaGas' medium- term normalized EPS growth rate 140% 120% 100% 80% 60% 40% 20% Peer 1 Peer 2 Peer 3 Peer 4 Peer Average Peer 5 Peer 6 Peer 7 Peer 8 ALA I $1.60 Announced 5% 6% 7% $1.40 $1.20 $1.00 $0.80 2020 2021 2022 2023E 2024E 2025E 2026E 2027E 2028E Notes: 1) Non-GAAP financial measure, see discussion in the advisories. Peer payout ratios based on 2024 estimates from Factset; *See "Forward-looking information" AltaGas Dividend Recommendation Aligns with Medium Term Normalized EPS Growth 8#9Strong Investment Capacity Cashflow Growth Drives Expanding Investment Capacity Prudent Capital Allocation with Investment Capacity Growing in Years Ahead Balance Sheet Capacity Net Debt/normalized EBITDA¹ target of 4.5x Monetization of non-core assets Larger capacity once Pipestone II and REEF are fully operational Shareholder Returns Target mid-single digit average annual EPS1 CAGR between 2024-2028 Target payout ratio of ~50-60% EPS Dividends can grow up to EPS growth Annual Investment Capacity ~$0.3B 2024E ~$1.3-1.5B 2024E-2028E Optional Capital ~$0.4B Organic growth Tuck-in M&A Debt Reduction Share buybacks, once leverage targets reached ARP ~$0.4B Organic Growth Prioritize Midstream maintenance and Utilities system betterment/customer growth (modest rate base growth) Utilities modernization programs and core Midstream growth projects I Other optional capital can be deployed, post those priorities Approximately one third of growth capex is related to Utility ARP investments CFO Dividends Paid Incremental Debt Capacity² Maintenance ~$0.4B (Utilities Depreciation + Midstream Sustaining) Investment Capacity | Capital allocation utilizes risk-adjusted project hurdles and ranks against | I the various alternatives, including competing projects, repayment of debt, M&A, and share buybacks (post reaching leverage targets). Notes: 1) Non-GAAP measure; see discussion in the advisories; 2) Incremental debt capacity is additional debt that can be taken on while holding leverage ratios flat; *See "Forward-looking Information" AltaGas Meaningful Enterprise Investment Capacity; Reinvestment Grows Investment Capacity 9#10Capital Allocation Framework Disciplined capital allocation within an equity self-funding model delivers shareholders value. Financial Strength and Flexibility Self-funded Organic Growth ☐ Strong balance sheet (4.5x) 1 2 ■ Focus on risk adjusted ☐ Reasonable dividend payout per share growth ☐ Excess investment capacity (equity self-funded) Notes: *See "Forward-looking Information" AltaGas 3 Sustainable Dividend Growth with Long-term Potential for Buybacks Steady and growing dividends Share buybacks can supplement dividends on an opportunistic basis Disciplined Capital Allocations = Maximum Shareholder Value 10#11Balance Sheet is Structured to Weather the Current Environment Floating Rate Exposure Minimized Interest rate exposure well-hedged with >90% of borrowing costs tied to fixed instrument or held at the utilities with rate recoverable structure. 11% increase in fixed rate debt since 2022 4% 88% Fixed O Floating - Utilities (Rate Recoverable) 8% Floating - Midstream / Corporate (Includes Pipestone Cash Consideration) As of Q3/23 Notes: *See "Forward-looking Information" AltaGas Properly Tenured Maturity Ladder Minimal near-term maturities with debt stack properly tenured to manage current rate environment. Purposeful flexibility left for debt reduction generated from an MVP sale. Medium-Term Note Maturities (C$MM) $0.9B $0.8B $0.6B $0.5B $0.6B $3.7B Optimized Preferred Redemptions Redemption of prefs with hybrid issuances has generated significant relative savings over reset by optimizing tax deductions / avoiding Part 6.1 taxes. $18MM Annual Cost Savings Cumulative impact from last three Pref-to- Hybrid transactions expected to generate Outstanding Series A/B Preferred Shares - $200MM Series G/H Preferred Shares - $200MM (Pending) Redeemed/ Hybrid Series K Pref Replaced with 5.25% Series 1 Hybrid Series C Pref Replaced with 7.35% Series 2 Hybrid Series E Pref Replaced with 8.90% Series 3 Hybrid 2024 2025 2026 2027 2028 2029 & Beyond Note: Series | Preferred was redeemed in 2020 for senior debt Balance Sheet is Positioned to Operate in Current Environment and Fund Robust Growth Pipeline 11#12Driving Towards Our Targeted Capital Structure ☐ ■ Sale of MVP is the quickest path to accelerate deleveraging: ~4.5x net debt / normalized EBITDA Additional financial flexibility also expected once Pipestone II and REEF are fully online Asset optimization, organic growth, cost management, and disciplined capital allocation will further enhance financial flexibility 8.0x 7.0x Canadian Midstream - 2024E Net Debt/ Normalized EBITDA 6.0x 5.0x 3.50x 4.0x 3.0x 2.0x 1.0x 0.0x Peer Range - Low, Average, High More ideal Long-term Range U.S. Gas LDCs - 2024E Net Debt/ Normalized EBITDA 5.25x Peer Range - Low, Average, High More ideal Long-term Range • Additional financial flexibility post Pipestone II and REEF developments coming online • Build dry powder and natural deleveraging overtime I 45% Weighted to Canadian Midstream I 55% Weighted to U.S. Gas LDCs Notes: 1) Non-GAAP measure; see discussion in the advisories; *See "Forward-looking Information" AltaGas Clear Path to Achieve 4.5x Net Debt/Normalized EBITDA Leverage Target 4.5x Target 12#13Commercial De-risking will Drive Long-term Value AltaGas Midstream AltaGas Utilities Notes: *See "Forward-looking Information" AltaGas ■ Medium-term Global Exports tolling target of 60%+ Active and systematic hedging for residual commodity exposure ■ Focus on take-or-pay and fee-for-service contracting Customer and resource play diversification ◉ Long-term cost contracting (Five-year CN agreement, VLGC time charters, etc.) ◉ ■ Utilize ARP modernization programs to upgrade assets and improve safety and reliability (provides an appropriate immediate return on investments through rate riders) ◉ Remain active and persistent on rate cases to minimize regulatory lag Pursuing weather and usage normalization across jurisdictions (currently in place in Virginia and Maryland) Advocating for prescribed timelines in D.C. Acute Focus on Reducing Risk Through Commercial Frameworks 13#14Delivering on Core Objectives ◉ Taking Active Steps to Drive an Appropriate Premium Valuation ◉ Delivering on these variables is key for long-term energy infrastructure investor demands ■ ~4-5% Dividend Yield ■ 50-60% Earnings Payout Ratio Sustainable Dividend Growth Notes:. *See "Forward-looking Information". AltaGas Steady Dividend Key Attributes Visible Growth for Premium Valuation Low Risk Strong Balance Sheet Contracted Commercial Framework Managed Commodity Exposure Equity Self-Funded Model Regular smaller brownfield expansion optimization with low-to-modest capex investments Deploy AltaGas' Investment Capacity Balancing Energy Infrastructure Investors Desire for Growth, Income and Low Risks 14#15ESG Goals and Performance Governance 91% Independent Directors Average Tenure N8 years 46% <5 years 36% 5-10 years 18% >10 years Average Age ~65 27% <60 years 27% Environment UTILITIES ENERGY EVOLUTION 2030 Goal ≥30%+ Scope 1 & 2 GHG emissions (WGL) 2022 2030 Goal ≥10% of fuel delivered from lower-carbon sources (WGL) Social DIVERSITY & INCLUSION 2030 Management Goal 40% (Female) 2022 20%1 (Under-Represented) 2022 60-65 years 2008 46% >65 years 20% 2030 Target Reduction 29% 17% D: BOARD Diversity Goal 50% (Female and ethnic/racial) by 2025 Notes: *See "Forward-looking Information" AltaGas 50% Achieved 64% MIDSTREAM ENERGY EVOLUTION 2030 Goal 40%+ Scope 1 & 2 GHG emissions intensity 2022 2026 Goal 15%+ Scope 1 GHG emissions (Harmattan) 2022 SAFETY TRIF Goal 1.20 1.99 PMVIR Goal 1.30 1.54 1.30 1.20 2019 10% 2030 Target 2019 10% 2026 Target 2022 2026 2022 Reduction Reduction Target 2026 Target Continuous Progress Focus Areas 15#16Continuing the Longer-term Journey of Compounding Normalized Earnings Per Share¹ Normalized EBITDA¹ 5-year 11% CAGR 5-year 6% CAGR Net Debt / Normalized EBITDA¹ Stock Performance 19 20 21 22 23E 24E 19 20 21 22 23E 24E 18 19 20 21 22 23E 24E 11% Normalized EPS CAGR 2019-2024E 6% 4.5x Net Debt / Normalized Normalized EBITDA CAGR 2019-2024E EBITDA Reduction 2018YE Q3/23TTM Dec-19 Aug-20 Apr-21 Dec-21 Aug-22 Apr-23 ALA-CA LDC Index Midstream Index Blended Index >10% Annual TSR Outperformance since 2019 Dividends + Share Price Notes: 1) Non-GAAP financial measure, see discussion in the advisories. 2) "E" denotes: normalized EPS guidance ranges of $1.85-$2.05 (2023) and $2.05-$2.25 (2024), and normalized EBITDA guidance ranges of $1.5B-$1.6B (2023) and $1.675B -$1.775B (2024); *See "Forward-looking information" AltaGas Long-term Outputs Align with Strategy 16#17Macro Set Up Macro Data Points Interest Rates 2022 2023 Utility Key Macroeconomic Data Points nil 4x Cost of Gas Substitution Inflation 2023 2022 Low High Below Avg Population Growth Midstream Key Macroeconomic Data Points Weak Robust Asian Demand for LPGs AltaGas Weak Commodity Prices Robust FX (USD/CAD) 2023 2022 Above Avg Low Regulatory Jurisdictions Weak Robust Producer Economics Sources: U.S. Bureau of Labor Statistics and U.S. Census Bureau, AGA, Bloomberg, Regulatory Research Associates and FactSet. Notes: *See "Forward-looking Information" High Investment Opportunities Low High Investment Opportunities 17#18Global Energy Demand Continues to Compound Population Growth and Rising Mobility Drive Strong Long-term Outlook Global Energy Demand (1990-2050) (MMboe/d) 450 ■Gas ■ Oil 400 Coal Nuclear 350 ■Renewables Biomass 300 250 200 150 100 50 90 95 00 05 10 10 15 20 25 25 30 35 40 40 Long-term energy demand expected to grow through 2050, driven by global population growth, rising mobility and economic expansion. 45 45 50 Conventional Energy Demand: Coal, Oil/Liquids and Natural Gas (1900-2022) 250 10 Coal Oil Gas -Population 9 200 Conventional Energy Demand (MMboe/d) 150 100 Calls for precipitous declines in conventional energy are intellectually dishonest. 50 50 0 €006 L 1910 1920 1930 1940 1950 1960 1970 1980 1990 2000 2010 2020 2030 2040 2050 Few things more correlated than population growth, prosperity, and energy usage. All forms of energy needed on the road ahead. Sources: Wood Mackenzie; Refinitiv/Reuters; Notes: See "Forward-looking Information" AltaGas Long-term Demand and Investment Thesis to Support Midstream and Utilities Growth 8165 43 22 0 Global Population (Blns) 18#19(MMboe/d) NW 20 10 30 40 90 80 70 60 50 Fundamentals for Natural Gas and NGLs are Robust Natural Gas and NGL Adoption is Strong Across Emerging Markets, Driving Structural Tailwind Global Natural Gas Demand (1990-2040) Global NGL Demand (1990-2040) 90 95 00 05 50 Natural Gas remains critical for energy affordability, reliability, and emission reductions. (MMBbl/d) 18.0 Asia-Pacific 16.0 Middle East Africa FSU 14.0 Europe I Latin America 12.0 I North America 10.0 8.0 ONA O 4.0 2.0 6.0 0.0 10 15 20 25 30 35 90 90 95 00 05 10 15 40 Sources: Wood Mackenzie; Refinitiv/Reuters; Notes: LPG includes propane and butane; See "Forward-looking Information" AltaGas Global Natural Gas and NGL Adoption Continued to Expand 20 20 25 30 35 40 40 Strong global NGL demand growth expected through 2040, led by Asia. 19#20(MMtherms/household) Gas Utilities Critical for Long-term Energy Delivery Affordability, Reliability and Climate Benefits Remain Strong Annual U.S. Household Energy Demand Gas vs. Electric Cost of Electricity Over Natural Gas Delivered Electrification Costs Household Energy Bills 6.0x 120 Natural Gas Electricity U.S. Average 5.0x 100 80 60 40 20 4.0x 3.0x 200% 175% 150% U.S. Average 125% 100% 75% 50% 25% 0% U.S. Average Michigan Virginia Maryland liiii l… …. 2.0x 1.0x 0 - 0.0x Michigan Virginia Maryland District of Columbia U.S. Average Michigan Virginia Maryland District of Columbia District of Columbia U.S. Average U.S. Average Demand for natural gas within AltaGas' jurisdictions represents ~70% of total household energy consumed. The current delivered cost of electricity over natural gas is approximately three times. Sources: Energy Analysis, AGA; RRA; Internal Analysis Using US Government Reported Public Information.; Notes: internal calculation, based on 2022 data, measured using therms equivalent. AltaGas Gas Utilities are Irreplicable Switching to an all-electric home would increase the average monthly bill by ~$275 (>75% of the average monthly household savings). 20 20#21Natural Gas Conversion Efficiency Leads the Industry Direct Gas Delivery to End Users Drives the Lowest Energy Loss Through the Value Chain SOURCE ENERGY EXTRACTION, PROCESSING GENERATION & TRANSPORTATION Direct Use of 100 Natural Gas MMBtu -7 MMBtu wwwww No energy conversion necessary, therefore no energy is lost DISTRIBUTION -1 MMBtu DELIVERED TO CUSTOMER 92 MMBtu ☐ SOURCE ENERGY EXTRACTION, PROCESSING & TRANSPORTATION Converting to Electricity 100 MMBtu 4 -5 MMBtu Generation and Distribution -57 MMBtu Sources: Energy Analysis, AGA; 1) Based on the national weighted average mix of power generation at the time of study. Notes: *See "Forward-looking Information" AltaGas DELIVERED TO CUSTOMER 38 MMBtu ME Natural Gas Direct Deliver Does not Face Traditional Energy Value Chain Leakage 21#22DMV Population and Demographics Provide Strong Tailwind Population Growth Across WGL Service Territories¹ (2012-2023) Cumulative Customer Additions Across WGL² (2012-2023) 200,000 16% WGL service territories are growing 180,000 WGL has added new 14% 50% 160,000 12% faster than the national 140,000 10% average 120,000 customers at ~1% per year over the past decade 8% I 100,000 6% 80,000 4% 60,000 2% 0% 40,000 VA MD D.C. WGL U.S. National Average 20,000 AltaGas 2012 2013 2014 2015 2016 2017 2018 2019 2020 2021 2022 2023E Customer additions is a foundational core platform growth story 22 22#23Electrification Would Increase Emissions and Cripple Economic Activity MMBtu/year 160 120 00 80 Household Energy Use and Emissions¹ (Natural Gas vs. Electric) 1 2 Current PJM Grid Generation Capacity Mix² <30% 10 of PJM electric 80 power generation 45% 160 Mt/House comes from nuclear + renewables Without Gas, Economic Durability Drops German Industrial Sector Cutting Production Due to High Natural Gas Prices Г 12% CNBC 17% High Natural Gas Prices 22% Lead to a Shutdown of British Fertilizer Plants The New York Times L 1 2 40 + 0 2 Electric Home Natural Gas Home CO2 Emissions An electric home consumes 42% more energy than a natural gas home. An electric home also produces 23% more CO₂ than a natural gas home. Natural Gas Coal Oil Nuclear Renewables Other California and Texas Power Outages³ (Outages Not Caused by Human Attacks) 28 24 >2x More Outages over 5 years 3 13 12 2018 2022 ■California Texas Sources: 1) Energy Analysis, AGA, based on 2021 data; 2) PJM disclosures, and 3) U.S. Department of Energy. Notes: See "Forward-looking Information" AltaGas Electrification Doesn't Mean Lower Emissions 4 Commercial and Industrial Customers Saved more than US$500 Billion using AGA Natural Gas Over the Past Decade Industrial development and economic activity stalls without affordable natural gas. Electrification is causing marked deterioration in energy reliability. 23#24Despite Negative Rhetoric, Natural Gas is the Long-term Solution Percent of Household Energy Demand (Natural Gas vs. Electricity) Electrification Lacks Pragmatism (Electricity vs. Natural Gas Costs) Switching to electricity from gas The Rising Push Back on U.S. Natural Gas Bans 1 100% 80% 60% 40% 20% 0% Michigan Virginia % Nat Gas Maryland DC National Average % Electricity would: A Cost 3.2x B the cost of gas¹ Wipe out more than 75% of U.S. household monthly savings² Cripple the ~12% of people living below the poverty line across our jurisdictions Natural Gas accounts for nearly 70% of U.S. household energy demand, but only represents a third of home energy costs.1 Sources: Energy Analysis, AGA; RRA; Internal Analysis Using US Government Reported Public Information. Notes: 1) Based on national average (Michigan 4.8x, Maryland 2.6x, D.C. 2.6x, and Virginia 2.5x); 2) Does not assume heat pumps are installed across entire installed housing stock and based on historical data. *See "Forward-looking Information" 2 3 Local gas bans and electrification codes in new buildings Adopted State legislation prohibiting local governments from restricting natural gas utility service Passed Introduced In Development There are >3x as many states banning gas bans than states adopting gas bans. Federal Courts have rejected gas ban legitimacy and highlight the right to choose. Federal Appeals Court Throws Out Berkeley, California's Ban on Natural Gas Ninth U.S. Circuit Court of Appeals in San Francisco AltaGas Natural Gas is Critical to Energy Transition, Electrification of Space Heating will take Decades 24#25(MBbl/d) Canadian Midstream Set-up is Compelling Rising WCSB Production and Global Connectivity Underpin Strong Multi-year Growth Trajectory WCSB NGL Supply Growth (2020-2030) Asian LPG Demand (2015-2050) 2000 1500 1000 500 (MMBbl/d) 7.00 China India 6.00 Japan South Korea 5.00 Indonesia Other Asia 4.00 3.00 2.00 1.00 0 0.00 2020 2021 2022 2023 2024 2025 2026 2027 2028 2029 2030 15 20 25 30 35 40 45 50 Canadian NGL supply expected to rise by ~500 MBbls/d through 2030 - while North America demand will be flat. Growing WCSB NGLS require additional market access. Asian LPG demand is expected to grow through 2050, led by China and India. Asia's growing LPG import needs will drive higher calls on Canadian exports. Sources: Wood Mackenzie; Refinitiv/Reuters; Notes: 1) LPG includes propane and butane; *See "Forward-looking Information" AltaGas Rising Domestic Supply and Rising Global Demand Underpin Compelling Investment Thesis 25 25#26MBbl/d Asian LPG Import Demands to Grow ~45% by 2040 Propane and Butane Imports to Grow from 2.5 MMBbl/d to 4.0 MMBbl/d Asian Propane Import Demand (2022 → 2040) (Domestic Demand - Domestic Supply = Import Requirements) 2500 ■China Japan Korea 2000 Other Asia-Pacific 1500 1000 500 0 2022 42% Increase by 2040 2040 1 MBbl/d Asian Butane Import Demand (2022 → 2040) (Domestic Demand - Domestic Supply = Import Requirements) 2000 China ■Japan Korea 1600 Other Asia-Pacific 1200 800 400 0 2022 48% Increase by 2040 Asian propane import needs will continue to grow in the coming decades, supporting higher Canadian exports. Includes strong PDH demand in China, and heating, transport and other uses in Japan, Korea and other regions. Source: Energy Aspects. Notes: *See "Forward-looking Information" AltaGas Asian butane import needs will continue to grow in the coming decades, supporting higher Canadian exports. Includes growth in cooking, blending and other end markets. Robust Asian Demand is Expected to Grow 2040 26 2 I ר#27I 2020 2021 2022 2023 2024 2025 2026 Bcf/d Canada: Natural Gas and NGL Outlook is Robust Canadian Natural Gas Production (2020-2030) WCSB NGL Outlook, by Product (2020-2030) WCSB NGL Outlook, by Play (2020-2030) 25 2,000 2,000 Cardium Deep Basin Duvernay Ethane Propane Montney Others 1,800 Butane Natural Gasoline 1,800 Cardium Deep Basin Alberta Montney BC Montney Duvernay Other Field Condensate 20 1,600 1,600 1,400 1,400 15 MBbl/d 1,200 1,200 1,000 Montney 10 LPGs MBbl/d 1,000 Montney 10 800 800 600 600 5 400 NGLS 400 Deep Basin 200 200 Deep Basin 0 0 Sources: Wood Mackenzie. Notes: *See "Forward-looking information" AltaGas Canada Set to Show Significant Gas/NGL Growth 2020 2021 2022 2023 2024 2025 2026 2027 I 2028 2029 I Canadian gas production to rise by 40% through 2030 to >22 Bcf/d. Canadian NGLs production to rise by >35% over the same period with limited domestic demand growth. I Montney to represent 65% of total production growth through 2030; Deep Basin will also march higher. 2030 27 2020 2021 2022 2023 2024 2025 2026 2027 2028 2029 2030#28AltaGas MBbl/d 800 700 600 500 400 300 200 100 0 2020 Alberta Montney NGL Outlook (2020-2030) Alberta: Marked Montney Liquids-rich Growth on Horizon 2023 2024 Pipestone Growth Area AB Sands Kakwa Core Ante Creek ■Kaybob Elmworth ■Mulligan Grande Prairie Pouce Coupe 0 2020 MBbl/d 50 50 100 2021 150 200 2022 250 ■Bluesky Charlie Lake ■Dunvegan 2023 Deep Basin NGL Outlook (2020-2030) Harmattan Growth Area Alberta Montney expected to be the largest NGL supply in Canada, representing 40% of Canadian production by 2030. Source: Wood Mackenzie; Notes: See "Forward-looking Information" Alberta Deep Basin expected to also show upwards of 30% NGL supply growth by 2030. Recent M&A activity reiterates growth potential. Energy Fundamentals are a Tailwind for Midstream 2024 2025 2026 ■Falher Glauconitic Notikewin Wilrich 28#290 2018 2019 B.C. Well Permits 1 B.C. well permits up >300% Y/Y in 2023, driven by progressing resource stewardship efforts supporting longer-term development. 2 BC: Progressing Resource Stewardship Efforts Supports Development B.C. Well Permits (2018-2023 YTD) B.C. Montney NGL Supply, by Area (2020-2030) B.C. Montney NGL Supply, by Product (2020-2030) 500 1,000 900 800 500 Blueberry/Northern BC Ethane 450 ■Propane 450 A ■Dawson Creek Butane Natural Gasoline 400 400 Heritage Liquids Field Condensate 700 350 350 Other 600 300 300 >3x 500 MBbl/d 250 MBbl/d 250 LPGS 400 200 200 ✓ 300 200 100 150 150 Townsend Growth Area 100 100 NGLS 50 50 2020 2021- 2022- 2023- 2024- B.C. activity levels expected to rise accordingly. Source: Wood Mackenzie. Notes:*See "Forward-looking Information" AltaGas B.C. Development Activity to Accelerate; Existing Infrastructure Key for Stewardship Commitments 3 0 2020 2021 2022 2023 2024 2025 2026 2027 Additional frac and liquids handling capacity required. Leveraging existing infrastructure key for limiting ground disruption commitments. 29 2028 2029 2030#30Canadian LNG Developments Drive Adjacent Opportunities LNG CANADA Project Summary $48B Phase 1 LNG export facility in Kitimat, BC with an expected 2025 in- service date. Export Capacity Phase 1 14 mmtpa Phase 2: +14 mmtpa Associated LPGs¹ (Propane/Butane) Liquids Per Phase ~50 Mbbl/d 20-25 Mbbl/d $6.4B LNG export facility 7-8 Mbbl/d Woodfibre LNG in Squamish, BC with an 2.1 mmtpa expected 2027 in-service date. 3.5 Mbbl/d KSI LISIMS LNG $8.7B floating LNG export facility in Gingolx, BC with an expected 2027-2028 in-service date. • Others (Cedar, Tilbury I/II) $3B Cedar LNG (2027+, Haisla Nation, Pembina) • $0.6B Tilbury LNG 1B Expansion (2026, Fortis) • $3.3B Tilbury LNG Phase 2 (2027+, Fortis) Notes: 1) Associated Liquids yields from representative liquids rich Montney deep-cut gas processing plants. * See "Forward-looking information" AltaGas Canadian LNG Provide Structural Tailwinds 40-45 Mbbl/d 12 mmtpa 18-22 Mbbl/d 6.2 mmtpa 20-24 Mbbl/d 9-11 Mbbl/d 30#31MBbl/d 200 150 100 50 0 450 400 350 300 250 200 150 MBbl/d 100 50 0 WCSB Propane Supply Available for Exports (2022-2040) Traditional Regional Demand Eastern CAD Demand ☐ PDH Available to Export Excess Canadian LPGs Best Served in Premiere Asian Markets 2026 2027 2028 2029 2030 2031 2032 2033 2034 2035 2036 2037 2038 2039 WCSB Butane Supply Available for Exports (2022-2040) 350 300 Traditional Regional Demand Eastern CAD Demand Available to Export 250 Source: Wood Mackenzie. Notes: *See "Forward-looking Information" AltaGas 2032 2033 2034 2035 2036 2037 2038 2039 2040 2040 MBbl/d 350 300 250 200 150 100 I 50 2021 2022 2023 WCSB LPG Available for Exports (2022-2040) 2024 2025 2026 2027 2028 2029 The Marginal Canadian LPG Barrel Needs to be Exported Total LPG Available for Export 2030 2031 2032 2033 2034 2035 2036 2037 2038 2039 2040 31#32High Growth Rate Regulated Utilities Platform High Growth Utilities Platform ■ ~1.6 million customers with population growing ~40% faster than the national average¹ ~70% of revenue from residential customers Limited weather/usage sensitivity across ~70% of rate base ■ US$5.0 billion regulated rate base; ~9% CAGR since 2019 Strong and Transparent Growth 2024E Utility Revenues 70% Residential 30% Commercial & Industrial ■ Strong growth through customer additions and modernization programs ■ Modernization programs provide incentive to upgrade networks for safety and reliability with limited rate lag Utilities Breakdown Maryland Customers² Rate Base (US$MM)² Allowed ROE OD.C. Maryland 513,000 1,544 9.70% Washington Virginia 552,000 1,797 9.65% Gas D.C. 164,000 743 9.25% Virginia SEMCOENERGY Michigan 319,000 884 9.87% Notes: 1) United States Census Bureau, using data over the past 10 years; 2) As of June 30, 2023. *See "Forward-looking Information AltaGas Michigan 33#33Utilities Strategic Focus 1 Improve Returns 2 Invest in Core Platform 3 Growth Opportunities related to Climate Initiatives 4 Policy / Advocacy Leadership 527 Continue closing the ROE gap ■ Operate with regulatory, capital, and cost discipline Modernize network to enhance safety and reliability Customer growth System expansion ■ Focus on energy efficiency programs, emission reductions, and adding fuels of the future Build alliances with multiple advocacy groups focused on our customers best interests Ensure stakeholders understand the affordability, reliability, energy security, and climate benefits of gas ENCY ONG 115 Notes: *See "Forward-looking Information" AltaGas Active Steps will Drive Long-term Value Creation Washington 34#341 Improve Returns at WGL Allowed ROE 2019 |- ~$70MM of annual net income value creation1 +240 bps WGL Regulatory ROE increase since 2019 Achievement driven by regulatory, capital and cost discipline over the past four years 2023E ~$35MM of potential annual net income value creation¹ A A~100 bps Rate Cases: D.C. and Maryland Pending Rate Cases AO AB Lever to help partially offset D Ⓡ 20-40 bps Operational Excellence: Cost and efficiency management - internal + external + 20-40 bps Further Operational Excellence $15-25MM of potential annual net income value creation¹ D ℗ 30-60 bps Regulatory Lag: Rate lag associated with historical test year → 0-40+ bps Asset Optimization Exercise strong capital discipline. Utilize modernization programs to prioritize safety, reduce risks, and enhance reliability, and drive better outcomes for all stakeholders. 1. Based on a future projection of rate base. AltaGas Closing the Remaining ROE Gap is a ~$850MM Value Creation Opportunity² E AO Future State 35#352 Address Aging Infrastructure Utilities Positioned for Large Ongoing Investment Opportunities 2,000 1,500 D.C. 1,000 500 0 2,000 1,500 Maryland 1,000 500 0 2,000 1,500 Michigan 1,000 500 0 2,000 1,500 Virginia 1,000 500 0 L Notes: *See "Forward- looking Information" Pre 1940s 1940s AltaGas 1950s 1960s 1970s 1980s 1990s Iron Plastic Protected Steel Others Large backlog of pipe modernization representing substantial investment opportunities over the long-term 2000s 2010s 2020s AltaGas has a Large Backlog of Pipeline Replacements on the Horizon 36#362 Accelerated Replacement Programs The Foundation for Improved Safety and Reliability with Better Outcomes for All Stakeholders Over US$1.7 billion of System Reinforcement Projects over next 5 years APRP Maturity (Year) Washington Gas A WGL Company SEMCOENERGY GAS COMPANY Maryland D.C. Virginia Michigan Notes: US$1.7 billion in programs include approved and filed AltaGas 2023 2024 2025 US$330MM 1,2 US$115MM 2026 2027 2028 New STRIDE 3 Plan US$330MM 5-yr commencing 20241 Requested US$672MM 1,2 New PROJECTpipes 3 Plan US$672MM 5-yr commencing 20251,2,3 US$878MM Extension to be filed in 20264 Extension to be filed in 20244 US$768MM remaining on 5-yr SAVE Plan, commenced in 2023 US$54MM remaining on 5-yr Mains Replacements, commenced in 2021 Rolling Approved Modernization Programs Follow the Large Replacement Backlog Across the Network 37#372 Invest in Core Platform Investments in WGL since 2018 Material Decline in Leaks¹ ■New Business WGL SEMCO ■System Betterment/Other C$4.0 billion invested ARP Programs 55% reduction in leaks over the past five years ARP investments in WGL are paying off with material reductions in leaks; which is driving improved safety and reliability with environmental and emissions benefits. 2018 2019 2020 2021 2022 2023E 2018 2019 2020 2021 2022 2023E Notes: 1) Internal data, represents Grade 1 and 2 leaks. *See "Forward-looking Information" AltaGas Investments are Driving the Intended Outcomes 38#382 Advance System Expansion and Reliability Projects Advance pragmatic extension to service territory to bring natural gas to currently unserved customers A and progress long-term projects focused on improving system reliability B for the long-term. Washington Gas 10% of homes within the states we operate use propane, fuel oil, kerosene or other fuels other than natural gas or electricity for home heating. Frederick MARYLAND DISTRICT OF COLUMBIA Frederick WEST VIRGINIA Montgomery Clarke Loudoun Michigan 12.9% Warren Shenandoah Arlington Fairfax Prince George's VIRGINIA Prince William Charles Maryland 12.2% La Plata Charles County Expansion Virginia 9.5% St. Mary's SEMCO BA Keweenaw Pipeline ONTARIO Manistique to Newberry Connector BAY WISCONSIN MICHIGAN Thumb of Michigan Area Expansion Detroit BA Several service area extension opportunities being evaluated to extend mainline and bring gas to under/non-serviced communities. >220 miles of distribution line extension being considered to ensure long-term reliability for both served and unserved customers. Notes: *See "Forward-looking Information" AltaGas Extension and Reinforcement Opportunities Augment Ongoing System Modernization 39#393 Climate Initiatives Provide Incremental Investment Opportunities Utilities Investment Opportunities Core Utilities Operations: Energy Efficiency Programs System Betterment Modernization Programs (ARP) New Customer Connects Extension of Service Territory into New Neighborhoods Alternative Fuels: RNG H² Notes: *See "Forward-looking Information" AltaGas The energy evolution provides long-term opportunities to make ancillary investments that can reinforce the core utilities distribution business. It also provides an avenue to push for required changes in the regulatory constructs across our operating jurisdictions. Climate Focus Brings Material Long-term Opportunities for Gas Utilities 40 40#403 Other RNG Advancements WGL ■ WGL is advancing several RNG opportunities across ■ the DMV Currently, five to ten in-territory facilities are being evaluated WGL's focus is in-territory projects and interconnects, representing up to 4 bcf of annual supply potential Consistent with WGLS decarbonization plan, the Company anticipates acquiring 10-15 Bcf RNG from outside its service territory Projects will progress WGL towards 10% lower- carbon fuel goal ■ ◉ SEMCOENERGY Pursuing various RNG interconnect opportunities within Michigan Opportunities are focused on in-territory dairy farms and landfills Five potential projects are currently being evaluated with developers Discussions are in various stages, focused on understanding timing and costs ■ Several other RNG expansion opportunities are in the pipeline Total capex potential across all projects is upwards of $275-550MM¹. AltaGas' focus will be on rate base or "rate base-like" investments across the RNG value chain. Notes: *See "Forward-looking Information"; 1) Actual capital investment will vary based on construction costs and our role within the project RNG value chain. AltaGas WGL and SEMCO Continue to Advance Opportunities Across Service Territories 41#413 Energy Efficiency Priorities Marked Investments in Energy Efficiency Over Past Decade; Desire to Play Much Larger Role Energy efficiency represents more than 40% of the emissions abatement needed by 2040, according to the IEA Sustainable Development Scenario. WGL and SEMCO Continue to Execute Large Approved Energy Efficiency Plans Saved ~490 Thousand Tons GHG 1,2 Equivalent to ~61,200 Homes² Reduction since 2011 equivalent to ~61,200 homes energy use for one year through programs Since 2011 Numerous programs for financial support and decarbonization opportunities Residential • • • • Low-Income Assistance Programs Weatherization Assistance Programs Home Energy Audit Space and Process Heating Tune-Up • Strategic Energy Management Appliance and Equipment Rebates . Behavior Programs • Energy Star New Homes $250 $200 $150 $100 $50 WGL and SEMCO Cumulative Spending on Energy Efficiency Programs (2011-2023 YTD) SEMCO and WGL have spent > $250MM on energy efficiency programs since 2011 2011 2012 2013 2014 2015 2016 VA 2017 ■MD 2018 ■MI 2019 2020 2021 2022 2023YTD • • Energy Conservation Kits Residential Weatherization Projects . Gas Heat Pumps Hybrid Systems Net Zero Buildings Industrial • Boiler Energy Management System • Commercial • Combined Heat and Power • Microgrids • Demand Response Management Combined Heat and Power • Gas Heat Pump • Hybrid Heat Pump Notes: 1) Conversion from therms using EPA "Greenhouse Gas Equivalencies Calculator"; 2) Based on first year energy savings. *See "Forward-looking Information" AltaGas Strong Desire and Focus to Deploy More Capital and Resources into Energy Efficiency Opportunities 42#424 Leading Through Advocacy Effective Stakeholder Engagement Paves the Way for Balanced Outcomes AltaGas Energy Reliability • No issues on delivery when needed Energy Affordability • Cost practical for all customers Cost advantaged relative to substitutions Long-term Energy Needs Climate Modernization Efficiency initiatives Evolution (RNG, H²) Stakeholder Outreach Employees Customers Policy makers Governments/Regulators Balancing All Three Corners is the Key to Success Unions 43#43Premiere, Globally Connected Midstream Platform Robust long-term fundamentals, supported by West Coast LNG Industry-leading Montney footprint - positioned to attract volumes and value chain opportunities Visible near and long-term growth De-risking commercial framework Strong counter-party credit: ~80% investment grade customers and growing take-or-pay or fee-for-service (currently ~50%) 2024E Normalized EBITDA 1,3 Credit Quality 20% 27% ■ A- and Above BBB+ to BBB- BB+ to BB- 36% 53% RIPET Prince Rupert Blair Creek Montney Region Townsend North Pine Fort St. John Younger Gordondale Pipestone 1/11 Dimsdale (Pipestone Gas Storage) Duvernay Region + Pipestone Dimi (Pipe Gas Pipestone I/II Announced Pipestone Acquisition Fort Contract Type² Saskatchewan Edmonton EEEP 10% Deep Basin JEEP 35% ■Take-or-Pay & 1 Harmattan Cost-of-Service ■Fee-for-Service ■Differential Commodity Ferndale Empress Bakken Region 19% AltaGas Midstream NGL Fractionation Gas Processing Processing and Fractionation LPG Export Terminal Storage Facility 65 Truck Terminal Rail Transport HH Rail Pipestone Assets Gas Processing Storage Facility Notes: 1) Non-GAAP financial measure; see discussion in the advisories.; 2) Differential: Merchant unhedged Global Export and other marketing volumes; Commodity: Frac exposed volumes, hedged and unhedged.; 3) Totals may not add due to rounding; *See "Forward-looking Information" AltaGas Globally Connected Infrastructure 45#44The AltaGas West Coast Advantage USD/BBL $20 USGC to Japan Baltic Freight to Japan RIPET to Japan $15 2 $10 $5 Jan-18 Jan-19 Jan-20 Jan-21 Jan-22 Jan-23 Jan-24 Jan-25 ARABIAN GULF O 18+ days AltaGas' West Coast Advantage expands in times of shipping congestions. AltaGas' structural shipping advantage over the U.S. Gulf Coast and Arabian Gulf expected to continue. 10-11 days 25+ days ORIPET OFERNDALE USGC base case time savings over the U.S. Gulf Coast. ~60% North American West Coast LPG exports have a Panama canal 1 congestion can add 10+ days to shipping times (35+ days total). ~ 45% base case time savings over the Arabian Gulf. This leads to increase in U.S. Gulf shipping costs 2 and strengthens the AltaGas West Coast Advantage. Sources: Argus and Bloomberg. Notes:*See "Forward-looking Information" AltaGas Westcoast LPG Exports from AltaGas' Deepwater Ports Structurally Advantaged 46#45Battle of the Barrels Leaves Asian Tolling as Clear Winner RIPET Tolling has Averaged ~US$4/Bbl Netback Premium Over Conway Over the Past Two Years Excess Canadian propane and butane that is available for exports at Fort Saskatchewan A has two options - going to Asia B via rail and AltaGas global exports or going to the Southern U.S. (Conway or Mt Belvieu) via rail. FEI Index less all-in costs (export toll, rail, opex and maritime shipping) B Notes: *See "Forward-looking Information" AltaGas AltaGas Asia Tolling B + AltaGas Southern U.S. Exports AltaGas RIPET Tolling has averaged ~US$4/Bbl stronger all-in netbacks for shippers compared to sending to Conway Cover the past two years. Currently US$7/Bbl better on forward indicative year. AltaGas RIPET tolling has provided ~ US$4/Bbl Better propane netbacks vs. Conway the past two years. AltaGas AltaGas RIPET Points of Export AltaGas AltaGas Ferndale Local Alberta Pricing (No Liquid Index) A Fort Sask, AB Liquid U.S. LPG Markets CWY or MTB Index less all-in rail transport costs C Conway, KS RIPET Asian Tolling at Structural Advantage Relative to Conway or Belvieu Mount Belvieu, TX 47#46North America Balancing the Global LPG Market Global LPG Exports, By Country (2014-2023 YTD) MMBbl/d 4.0 3.5 3.0 2.5 2.0 1.5 1.0 0.5 AltaGas AltaGas delivers 16% of Japan's total propane imports 14% of South Korea's total LPG imports. Japan Home heating; more environmentally-friendly alternative to thermal coal. Approximately 90% of global LPG export volumes are delivered to Japan and South Korea. South Korea Propane is used for home heating and some petchem while butane is used for transportation and fuel blending. Strong Demand- pull from Asia 99% of global exports are transacted with investment grade counter parties or fully secured. 0.0 2014 2015 2016 2017 2018 2019 2020 2021 2022 2023 United Arab Emirates Qatar Saudi Arabia Norway ■Algeria United States Iran ■Kuwait I ALA Sources: Wood Mackenzie. Notes: *See "Forward-looking Information" AltaGas AltaGas Asia has strong demand- pull with robust demand for increased Canadian supply. China and Other Approximately 10% of global exports are delivered to China or other markets. Future larger growth potential with PDH additions. Despite Strong Growth, AltaGas Remains a Smaller Player in the Global Market with Robust Growth Opportunities 48#47Midstream Strategic Focus 1 Leverage and Optimize Existing Assets 2 ■ Focus on growing EBITDA through no- to low-capex investments 3 De-risk Operations Framework Strengthen the Midstream Value Chain 4 Evaluate Growth Opportunities ☐ Increased take- or-pay and tolling agreements Systematic hedging De-risk costs and supply chain ■ Stakeholder engagement Strengthen footprint across the value chain - G&P, frac, extraction, and liquids handling Greater NGL control Increase customer and geographic diversification ■ Allocate capital to the strongest risk- adjusted return projects Notes: *See "Forward-looking Information" AltaGas Asset Optimization and Selective Capital Deployment = Value Creation AltaGas AraGas 49#481 Leverage and Optimize Existing Assets Low-to-No- Capital- Intensive Projects Medium Capital- Intensive Projects Larger Capital- Intensive Projects Projects with <$25MM Capital Spend Projects with $25MM-$200MM Capital Spend Projects with >$200MM Capital Spend Advancing all three project types is key for near- medium- and long-term growth and value creation. Notes: *See "Forward-looking Information" AltaGas Large Range of Small, Medium and Large Optimization and Growth Opportunities 50 50#491 Low-to-No- Capital-Intensive Projects Projects with <$25MM Capital Spend 보리얼 파이어니어 BOREAL PIONEER Townsend: Whitespace Optimization Treaty 8 resolution provides visible path to optimization and increasing facility throughput. ■ Asset is highly contracted. with long-term take-or-pay contracts; active discussions around filling the non- contracted space. Long-term CN Agreement ■ New five-year CN Rail agreement provides cost and service predictability. Covers current RIPET exports and will also include REEF volumes, should the project be sanctioned. Maritime Time Charters ■ Extend value chain into Asia, reduces shipping costs by ~25% over long-term basis, and remove pricing volatility. ■ Three Time Charters operating in 2024 with a fourth under construction, which is set to be commissioned in H1/26. RIPET: Methanol Reduction Removing methanol from propane supply at RIPET expands downstream demand markets in Asia. Project Legend: Notes: *See "Forward-looking Information" AltaGas Sanctioned Advanced, Not Currently Sanctioned Under Evaluation 51#501 Medium Capital-Intensive Projects Projects with $25MM - $200MM Capital Spend Global Exports Logistics Optimizations ■ Continued to debottleneck global export capacity across rail, logistics and operations. ■ Projects in various stages and will be sanctioned over the next few years. Additional Frac and Liquids Handlings in NEBC ■ De-propanizer / de-butanizer at Townsend (add ~6,000 Bbls/d of liquids capacity). Additional 20,000 Bbls/d of fractionation capacity at North Pine. G&P Processing Expansions ■ Inlet capacity at various facilities, including Townsend and Harmattan. Dimsdale Expansion ■ Premiere natural gas storage facility in Alberta Montney. ■ Working gas capacity of 15 Bcf is expandable to 69 Bcf. ■ LNG balancing hub for Montney production mid- decade as LNG Canada comes online. Project Legend: Notes: *See "Forward-looking Information" AltaGas Sanctioned Advanced, Not Currently Sanctioned Under Evaluation 52#511 Larger Capital-Intensive Projects Projects with >$200MM Capital Spend Pipestone II ■100 MMcf/d sour deepcut processing facility with 20,000 Bbls/d of liquids handling capabilities. ■ 100% contracted under long-term take-or-pay agreements with marquee. independent and investment grade producers. REEF: LPG and Dock 50/50 JV with Vopak to develop large-scale LPG export terminal with a dedicated jetty. ■ Phase 1 capacity 50,000 - 60,000 Bbls/d of LPG export capacity. ■ Site clearing work underway with FID expected in H1/2024. REEF Bulk Liquids Capital efficient expansion of product offering with the addition of bulk liquids (methanol, diesel and bio- diesel). ☐ Project Legend: Notes: *See "Forward-looking Information" AltaGas Sanctioned Advanced, Not Currently Sanctioned Under Evaluation Pipestone III Strong customer demand for additional processing and liquids handling capacity. 53#522 Commercial De-risking A B Minimize Commodity Exposure ☐ Increase take-or-pay and fee-for-service contracting 2024E Normalized EBITDA¹, By Contract Type Medium-term global exports tolling target of 60%+ Take-or-Pay & Fee-for-Service Active and systematic hedging for any residual commodity exposure 46% 54% Differential & Commodity ■ Lock-in Operating Costs Lock in operating and logistical costs to provide long-term visibility for customers and reduce earnings volatility VLGC time charters 5-yr CN contract • Actively hedge any residual Baltic freight and diesel shipping costs Long-term Normalized EBITDA¹, By Contract Type C De-Risk Operations and Supply " Diversify across customer and geographic resource plays Secure long-term LPG export supply agreements ☐ Secure long-term off-take agreements with customers in Asia Notes: 1) Non-GAAP measure; see discussion in the advisories. *See "Forward-looking Information". AltaGas 30% Take-or-Pay & Fee-for-Service Differential & Commodity 70% Acute Focus on Reducing Risk Through Strong Commercial Frameworks 54#53Global Exports Tolling 2 Building the Long-term Commercial Stack ☐ Strong fundamentals and structural pricing advantage support tolling agreements as growing production increases the importance of LPG netbacks. ■ Interest across multiple customers, including Canadian producers, NGL aggregators, and Asian off-takers. Notes: *See "Forward-looking Information" AltaGas Expand Existing Global Export Tolling Agreement Commercial 2027+ Targeting ~100 MBbls/d Under Long- term Tolling Current Tolling New Producer Tolls Agreements New NGL Aggregator Tolls New Asian Offtake Tolls Export Capability 55#543 Strengthening the AltaGas Value Chain The Multifaceted Approach to Strengthening the Franchise Gas Gathering & Processing AltaGas Midstream NGL Extraction, Fractionation & Liquids Handling Transportation, Storage and Logistics Global Exports Medium-to- longer-term Growth Potential4 Pipestone I, Pipestone II, REEF, and Dimsdale 2.1 Bcf/d1 Processing 65,000 Bbl/d²; 6 Facilities 210 MMcf/d Processing Pipestone I/II sour deepcut processing in Alberta Montney ~15,000 Bbls/d+ C2+ volumes with ~6,500 Bbls/d of LPGs from Pipestone I/II 2-3%/year 2024-2028 ~4,700 rail cars, >6 MMBbl Storage ~150,000 Bbl/d³ Export capability + Up to 2-4%/year 15 Bcf/d Gas Storage Dimsdale storage asset ensures producer egress and provides other AltaGas value creation options 50,000+ Bbls/d Export Capacity ~6,500 11,500 Bbls/d Pipestone C3/C4 supply 2025-2028 Incremental Organic Growth Opportunities ■ Gas Processing Optimizations and Expansion ☐ Pipestone III Rolling Hills CCUS Townsend De-propanizer / De-butanizer North Pine Expansion C2+ Extraction Opportunities Dimsdale Expansion Pacific Northwest Hydrogen Hub REEF Future Expansion Phases (bulk liquids, C2 Exports) Notes: 1) Based on ALA working interest capacity in FG&P and extraction, based on nameplate capacity. 2) Based on ALA 100% working interest facilities and ALA % capacity in non-operated facilities, based on nameplate capacity 3) Includes RIPET and Ferndale. 4) Represents growth in the Midstream segment normalized EBITDA. *See "Forward-looking Information" AltaGas Building Blocks to Become Preeminent Midstream Platform in Western Canada + Up to 1-6%/year Longer-term 56#553 Pipestone Acquisition Strategic Acquisition that Strengthens Alberta Montney Footprint with High-quality Liquid-rich Assets Strategic Fit $650MM Purchase Price 50% cash and 50% AltaGas Shares Gas Gathering & Processing Risk Accretion Pipestone I: 110MMcf/d Pipestone II: 100MMcf/d NGL Liquids Handling Dimsdale Gas Storage Leverage and Balance Sheet 40,000 Bbl/d 15 Bcf Expandable to 69 Bcf Financially Attractive On strategy. ■ Geographic diversification into the Alberta Montney that expands customer base. ■ Growth accretive. ■ Augment global exports with liquids. ■ 100% take-or-pay and fee-for-service. ■ Adds meaningful long-term LPG supply; ~3,500 Bbls/d in 2024; ~6,500 Bbls/d post Pipestone II; 11,500 Bbls/d potential long-term. ■ Credit accretive; reduces net debt to normalized EBITDA¹ by 0.1x in 2025+. ■ 5% normalized EPS¹ accretion once Pipestone II is onstream. Notes: 1) Non-GAAP measure; see discussion in the advisories. *See "Forward-looking Information" AltaGas Strategic and Financially Accretive Acquisition 57#563 Global Exports Optimization and Growth ■ Near, medium, and long-term optimization opportunities across platform. Will build on track record of growing from ~35 MBbls/d in 2019 to 110+ MBbls/d currently. ■ ■ Includes rail, logistics, and operations projects to improve connectivity and have lowest possible operating costs. REEF will provide benefits to RIPET, once online. RIPET Bbl/d 210,000 175+ MMBbls/d 180,000 150,000 RIPET Ferndale 120,000 90,000 60,000 30,000 Ferndale 2019 2020 2021 2022 2023E Long-term Capacity RIPET, Ferndale and REEF Propane Exports - BC Propane and Butane Exports - Washington State Notes: See "Forward-looking Information" AltaGas REEF LPG and Bulk Liquids Exports - BC 58#572024 Financial Guidance Highlights 6% Annual Dividend Increase $2.05-2.25 Anticipated Normalized EPS1 10% Y/Y Growth (2023 Midpoint to 2024 Midpoint) $1.675 -1.775B Anticipated Normalized EBITDA¹ 11% Y/Y Growth (2023 Midpoint to 2024 Midpoint) ~$1.2B Planned Capital Program AltaGas is focused on building a low-risk energy infrastructure platform that delivers resilient and durable value for our stakeholders that compounds over time. Notes: 1) Non-GAAP financial measure, see discussion in the advisories *See "Forward-looking information" 59#582024 Guidance Puts & Takes Tailwinds Headwinds Export Tolling & Merchant Volumes Global Export Margins ☑ Pipestone I and Dimsdale Contribution Utility Rate Base Growth ☑ Normal Weather (DC & MI) USD/CAD FX DC/MD Rate Case Timing Alaska Sale As highlighted in Q3/23, we expect to achieve results in the upper half of the 2023 normalized EBITDA guidance range. Lower MVP AFUDC Interest Expense Notes: 1) Non-GAAP financial measure; see discussion in the advisories; *See "Forward-looking Information" AltaGas Normalized EBITDA¹ Guidance ($ millions) - $1,500 $1,600 Utilities: ~55% - 57% $1,675 - $1,775 Utilities: ~ 53% - 57% Midstream: ~43% 45% Midstream: ~43% -47% 2023E 2024E Normalized EPS¹ Guidance $2.05 - $2.25 $1.85 - $2.05 5-year 11.5% CAGR 2019 2020 2021 2022 2023E 2024E Positioned to Deliver Top Quartile Y/Y EBITDA and EPS Growth in 2024 vs. Energy Infrastructure Peers 60 50#592024 Capex Budget 2024 Capital Budget: $1.2 Billion Largest 2024 capital outlays include Utilities ARP, System Betterment, and the Pipestone II facility. Increasing Midstream Allocation Strong organic growth opportunities across both platforms - driving healthy competition for capital. Attractive opportunities in Midstream driving increased allocation. Corporate/Power 6% Midstream: Maintenance & Turnaround ☐ Pipestone II ☐ Optimization capital Utilities 58% Midstream 36% Utilities: ☐ ARP/MRP Programs " Customer Growth System Betterment 2% 1% 1% 2% 6% 58% 70% 78% 89% 87% 36% 28% 20% 10% 12% 2020 2021 2022 2023E 2024E ■ Utilities Midstream Corporate/Power Notes: *See "Forward-looking Information" AltaGas Significant Growth Opportunities Require High-grading To Maintain Ability to Self-fund 61#602024 Hedging AltaGas Hedging Philosophy Wellhead ◉ ☐ Increase tolling and reduce commodity exposure to further stabilize Midstream cashflows Residual commodity exposures actively managed through hedging program Gas Gathering & Processing GAS NGLS NGL Extraction & Fractionation C3 & C4 C5 Transportation, Storage & Rail Logistics Export C3 & C4 C3 & C4 00000 boo ན་ Global Markets AltaGas No major commodity exposures Target minimum 80% hedged in 2024 Target of minimum 80% hedge prior to 2024 year end Currently 73% hedged, through combination of tolling and financials Global Export Volumes Hedged (Tolled/Financial) Target Hedge % 85% 78% 77% 51% 78% hedged for 2024E ocean freight via time charters, financial hedges and tolled volumes Three Time Charters in place for 2024, including delivery of Boreal Pioneer and Boreal Voyager Q1/24 Q2/24 Q3/24 Q4/24 Notes: *See "Forward-looking Information" AltaGas Active Risk Management to Enhance Cashflow Stability 62