Q3 2021 Earning Summary

Q3/21 Earnings Summary

October 28, 2021

Forward-Looking Information

FORWARD-LOOKING INFORMATION

This presentation contains forward-looking information (forward-looking statements). Words such as "may", "can", "would", "could", "should", "will", "intend", "plan", "anticipate", "believe", "aim", "seek", "propose", "contemplate", "estimate", "focus", "strive", "forecast", "expect", "project", "target", "potential", "objective", "continue", "outlook", "vision", "opportunity" and similar expressions suggesting future events or future performance, as they relate to 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: expected capital expenditure plan of approximately $850 million; planned segment allocation of 2021 capital expenditures; expected 2021 Normalized EPS guidance of $1.65 - $1.80 per share; expected 2021 Normalized EBITDA guidance of $1.475 billion - $1.525 billion; expected dividend yield; contract type and counterparty credit expectations in the Midstream segment, and anticipated retail/commercial EBITDA allocation in the Utilities Segment in 2021.

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: the U.S./Canadian dollar exchange rate, financing initiatives, the performance of the businesses underlying each sector; impacts of the hedging program; commodity prices; weather; frac spread; access to capital; timing and receipt of regulatory approvals and orders; timing of regulatory approvals related to Utilities projects; 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; and dividend levels.

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: risk related to COVID -19; health and safety risks; risks related to the integration of Petrogas; operating risks; regulatory risks; cyber security, information, and control systems; litigation risk; climate-related risks, including carbon pricing; changes in law; political uncertainty and civil unrest; infrastructure risks; service interruptions; decommissioning, abandonment and reclamation costs; reputation risk; weather data; Indigenous land and rights claims; crown duty to consult with Indigenous peoples; capital market and liquidity risks; general economic conditions; internal credit risk; foreign exchange risk; debt financing, refinancing, and debt service risk; interest rates; technical systems and processes incidents; dependence on certain partners; growth strategy risk; construction and development; transportation of petroleum products; impact of competition in AltaGas' businesses; counterparty credit risk; market risk; composition risk; collateral; rep agreements; delays in U.S. Federal Government budget appropriations; market value of common shares and other securities; variability of dividends; potential sales of additional shares; volume throughput; natural gas supply risk; risk management costs and limitations; underinsured and uninsured losses; commitments associated with regulatory approvals for the acquisition of WGL; securities class action suits and derivative suits; electricity and resource adequacy prices; cost of providing retirement plan benefits; labor relations; key personnel; failure of service providers; compliance with Section 404(a) of Sarbanes-Oxley Act; and the other factors discussed under the heading "Risk Factors" in the Corporation's Annual Information Form for the year ended December 31, 2020 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 press release, 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 (Management) 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.sedar.com.​

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, 2021. 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, COVID-19 related costs, 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 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, COVID-19 related costs, 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. Normalized funds from operations is calculated based on cash from operations and adjusted for changes in operating assets and liabilities in the period and non-operating related expenses (net of current taxes) such as transaction and financing costs related to acquisitions and dispositions, COVID-19 related costs, and restructuring costs. Normalized funds from operations is used to assist Management and investors in analyzing the liquidity of the Corporation. Management uses this measure to understand the ability to generate funds for capital investments, debt repayment, dividend payments, and other investing activities.

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.

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Key Highlights:

Strong Third Quarter Results Driving Better Outcomes for all Stakeholders

• Normalized FFO per share1 of $0.61 in the third quarter of 2021 compared to $0.40 in the third quarter of 2020, representing 53% year-over-year growth and continues to provide the foundation for increased returns of capital to shareholders and to fund ongoing organic expansion.
• Normalized EPS1 of $0.02 in the third quarter of 2021 compared to $0.04 in the third quarter of 2020 and positions AltaGas well to deliver on 2021 financial guidance.
• Normalized EBITDA1 of $244 million in the third quarter of 2021 compared to $213 million in third quarter of 2020, representing 15% year-over-year growth. Results reflected strong execution across the platform, particularly within the Midstream segment which demonstrated robust growth across the business.
• Midstream normalized EBITDA of $186 million in the third quarter of 2021 compared to $114 million in the third quarter of 2020, representing a 63% year-over-year increase. Performance included record global export volumes of liquified petroleum gases (LPGs) that averaged approximately 105,000 Bbls/d to Asia, an 11% year-over-year increase in gathering and processing volumes, and a 15% year-over-year increase in fractionation and liquids handling volumes.
• Utilities normalized EBITDA of $62 million in the third quarter of 2021 compared to $80 million in the third quarter of 2020. The largest factors behind the year-over-year decrease were the one-time pension accounting adjustment in the third quarter of 2020 and the unfavourable impact of the CAD/USD exchange rate, partially offset by continued Accelerated Pipeline Replacement (ARP) investments and the impact of the Maryland and D.C. rate cases.
• Washington Gas received approval from the Maryland Public Service Commission (PSC) to support the Piscataway Bioenergy Project, which is AltaGas' first renewable natural gas (RNG) project in partnership with the Washington Suburban Sanitary Commission (WSSC Water) to transform biowaste into renewable energy.
• Subsequent to quarter-end, AltaGas filed an application with the Canada Energy Regulator for a 25-year butane export license for 40,000 Bbls/d. The application is a proactive step to ensure AltaGas and its partners are positioned to continue to connect the growing LPG production volumes from Western Canada that exceed local demand to global markets, which benefits its upstream and downstream customers.

Q3 2021 Normalized EBITDA

Growth ($ millions)

213	244
Q3/20	Q3/21

Q3 2021 Normalized EPS

($/share)

0.04

0.02

Q3/20 Q3/21

1. Non-GAAP financial measure; see discussion in the advisories.

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Q3 2021 Financial Results Summary

Q3/21 Financial Results Summary

$244MM		$170MM		$5MM		$0.02
Normalized		Normalized		Normalized		Normalized
EBITDA1		FFO1		Net Income1		EPS1

Notes: 1. Non-GAAP measure; see discussion in the advisories

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Consolidated: Q3/21 vs. Q3/20

Core Businesses Demonstrate Strong Performance

Normalized EBITDA1

($ millions)

							20	244
				-1
				-11
			61			224
213	-38
		175
Q3 2020	Asset Sales &	Q3 2020	Midstream	Utilities	Corp/	Q3 2021	Deferred Hedging Loss	Q3 2021
Actual	One-Time Adjustments	Run Rate2	Growth	Other	Run Rate2	Actual

		▼ Pomona battery		▲ Petrogas consolidation	▲ WGL rate cases and	▼ Higher G&A due		▼ Deferred hedging
		storage		▲ Higher midstream and	ARP spending	to increased LTIP		loss on export
		▼ CES		export volumes	▲ Higher retail gas	associated with		volumes that will be
		▼ Ripon		▲ NEBC growth projects	margins	ALA's higher		settled on delivery
		▼ US Transportation		in service	▲ Higher returns on	share price and		in Q4/21 once
			LTI true-up.
		and Storage		▲ Lower NGL marketing	pension assets		cargos reach their
		▼ Pension accounting		margins	▲ Lower COVID-19			destination point.
		change		▼ MVP AFUDC	related impacts on
		▼ CEWS		▼ Shared G&A	usage and late fees.
				▼ Gordondale contract	▼ Higher G&A and
				amortization	Opex
					▼ USD/CAD exchange
					rate (1.26 vs. 1.33)

1.	Non-GAAP financial measure; see discussion in the advisories; numbers may not add due to rounding.	5
2.	Represents base business net of the impact of lost EBITDA associated with asset sales and certain one-time items.