Renewed, Reliable and Resilient March Investor Meetings

2 This presentation contains forward-looking statements based on current expectations, including statements regarding our earnings guidance and financial outlook and goals. These forward-looking statements are often identified by words such as “estimate,” “predict,” “may,” “believe,” “plan,” “expect,” “require,” “intend,” “assume,” “project,” "anticipate," "goal," "seek," "strategy," "likely," "should," "will," "could," and similar words. Because actual results may differ materially from expectations, we caution you not to place undue reliance on these statements. A number of factors could cause future results to differ materially from historical results, or from outcomes currently expected or sought by Pinnacle West or APS. These factors include, but are not limited to: uncertainties associated with the current and future economic environment, including economic growth rates, labor market conditions, inflation, supply chain delays, increased expenses, volatile capital markets, or other unpredictable effects; our ability to manage capital expenditures and operations and maintenance costs while maintaining reliability and customer service levels; variations in demand for electricity, including those due to weather, seasonality (including large increases in ambient temperatures), the general economy or social conditions, customer, and sales growth (or decline), the effects of energy conservation measures and distributed generation, and technological advancements; the potential effects of climate change on our electric system, including as a result of weather extremes such as prolonged drought and high temperature variations in the area where APS conducts its business; power plant and transmission system performance and outages; competition in retail and wholesale power markets; regulatory and judicial decisions, developments, and proceedings; new legislation, ballot initiatives and regulation or interpretations of existing legislation or regulations, including those relating to environmental requirements, regulatory and energy policy, nuclear plant operations and potential deregulation of retail electric markets; fuel and water supply availability; our ability to achieve timely and adequate rate recovery of our costs through our rates and adjustor recovery mechanisms, including returns on and of debt and equity capital investment; our ability to meet renewable energy and energy efficiency mandates and recover related costs; the ability of APS to achieve its clean energy goals (including a goal by 2050 of 100% clean, carbon-free electricity) and, if these goals are achieved, the impact of such achievement on APS, its customers, and its business, financial condition, and results of operations; risks inherent in the operation of nuclear facilities, including spent fuel disposal uncertainty; current and future economic conditions in Arizona; the direct or indirect effect on our facilities or business from cybersecurity threats or intrusions, data security breaches, terrorist attack, physical attack, severe storms, or other catastrophic events, such as fires, explosions, pandemic health events or similar occurrences; the development of new technologies which may affect electric sales or delivery, including as a result of delays in the development and application of new technologies; the cost of debt, including increased cost as a result of rising interest rates, and equity capital and the ability to access capital markets when required; environmental, economic, and other concerns surrounding coal-fired generation, including regulation of GHG emissions; volatile fuel and purchased power costs; the investment performance of the assets of our nuclear decommissioning trust, pension, and other postretirement benefit plans and the resulting impact on future funding requirements; the liquidity of wholesale power markets and the use of derivative contracts in our business; potential shortfalls in insurance coverage; new accounting requirements or new interpretations of existing requirements; generation, transmission and distribution facility and system conditions and operating costs; the ability to meet the anticipated future need for additional generation and associated transmission facilities in our region; the willingness or ability of our counterparties, power plant participants and power plant landowners to meet contractual or other obligations or extend the rights for continued power plant operations; and restrictions on dividends or other provisions in our credit agreements and ACC orders. These and other factors are discussed in the most recent Pinnacle West/APS Form 10-K along with other public filings with the Securities and Exchange Commission, which you should review carefully before placing any reliance on our financial statements, disclosures or earnings outlook. Neither Pinnacle West nor APS assumes any obligation to update these statements, even if our internal estimates change, except as required by law. In this presentation, references to net income and earnings per share (EPS) refer to amounts attributable to common shareholders. Forward Looking Statements

1. Company Profile 2. Accomplished Previous Goals & 2022 Rate Case Outcome 3. Growth Outlook & Energy Future 4. Financial Outlook Table of Contents

Key Facts as of Dec. 31, 2023 Consolidated assets $25B Market cap $8.15B Generating capacity owned or leased (year end) 6.5GW Customers 1.4M Current % from clean energy 51% Retail Sales Mix (Non-Residential/Residential) 51%/49% Service Territory 5 Arizona’s Largest Electric Company

Accomplished Previous Goals & 2022 Rate Case Outcome

✓ Improved customer experience ➢ From 4th quartile in 2021 to 2nd quartile in 2023 J.D. Power Residential and Business Survey ✓ Top quartile reliability for 10 of the last 11 years ✓ Successfully appealed 2019 rate case ✓ Improved relationships and developed a supportive regulatory environment ➢ Constructive decisions from ACC (Power Supply Adjuster, 2019 Rate Case appeal outcome, 2022 Rate Case) ✓ Achieved an improved ROE of 9.55% and 0.25% FVI with a new generation capital rider ✓ Deferred equity issuance until post-rate case to limit dilution ✓ Continued to grow dividend during financial reset 7 Accomplished previous goals set during the financial reset

Return on Equity 9.55% Fair Value Increment 0.25% Equity Ratio 51.93% Post Test-Year Plant 12 months + Four Corners ELG New Capital Tracking Mechanism System Reliability Benefit surcharge approved Existing Adjustors • Partial transfer of LFCR funds to base rates • PSA annual cap increase approved Total Base Rate Increase $491.7M Total Net Increase $253.4M Customer Net Impact on Day 1 8% 8 Key Components of Final Decision The 2022 rate case outcome was reasonable and constructive

Growth Outlook & Energy Future

1. Rapidly growing service territory with a diverse customer base 2. An improved regulatory environment 3. Making progress toward our clean energy commitment 4. Tremendous opportunities in transmission growth 5. Continue to focus on customer affordability and have a customer centric strategy 10 KEY REASONS We are focused on solid execution and are optimistic for the future

2.1% 2.3% 2.4% 2.2% 2.1% 1.5%-2.5% 0% 1% 2% 3% 2019 2020 2021 2022 2023 2024E Residential Customer Growth1 APS Residential Growth Natn'l Avg.-Residential 11 • Latest census data places Maricopa County as the fastest-growing county in the nation with the most net domestic migration • Phoenix housing is affordable compared to major cities in the region • Phoenix is ranked #1 out of 15 top growth markets for manufacturing by Newmark Group, a global real estate firm • Maricopa County leads the nation in attracting talent according to Lightcast, a global leader in labor market analytics Arizona economy continues to be robust and attractive 1 National average from 2023 Itron Annual Energy Survey Report. Arizona continues to be an attractive service territory with strong customer growth REASON #1

• Infrastructure ─ close proximity to major markets in the West with accessibility by rail or truck • Weather predictability ─ low propensity for natural disasters and greatest solar irradiance in America • Workforce availability ─ three major universities graduating a skilled labor force • Affordability ─ business friendly policies and regulation • Clean Energy ─ IRA support for clean energy generation • Accounts for 3%-5% of the 4%-6% long-term weather normalized sales growth1 guidance • Amplifier effect for jobs and surrounding communities leading to residential growth • Increased sales help spread fixed costs and maintain rate affordability for all customers Large C&I customers as a growth driver Arizona is an attractive location for business growth Best-in-class service territory supports high tech growth and economic development REASON #1 12 1 Forecasted guidance range through 2026.

Source: Arizona Commerce Authority 13 Arizona’s commercial and industrial growth is diverse REASON #1