8-K

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM 8-K

CURRENT REPORT

Pursuant to Section 13 or 15(d) of the

Securities Exchange Act of 1934

Date of report (Date of earliest event reported):    April 29, 2016

Commission File Number	Exact Name of Registrant as Specified in Charter; State of Incorporation; Address and Telephone Number	IRS Employer Identification Number
1-8962	Pinnacle West Capital Corporation (an Arizona corporation) 400 North Fifth Street, P.O. Box 53999 Phoenix, AZ 85072-3999 (602) 250-1000	86-0512431
1-4473	Arizona Public Service Company (an Arizona corporation) 400 North Fifth Street, P.O. Box 53999 Phoenix, AZ 85072-3999 (602) 250-1000	86-0011170

Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation of the registrant under any of the following provisions:

¨ Written communications pursuant to Rule 425 under the Securities Act (17 CFR 230.425)

¨ Soliciting material pursuant to Rule 14a-12 under the Exchange Act (17 CFR 240.14a-12)

¨ Pre-commencement communications pursuant to Rule 14d-2(b) under the Exchange Act (17 CFR 240.14d-2(b))

¨ Pre-commencement communications pursuant to Rule 13e-4(c) under the Exchange Act (17 CFR 240.13e-4(c))

This combined Form 8-K is separately filed or furnished by Pinnacle West Capital Corporation and Arizona Public Service Company. Each registrant is filing or furnishing on its own behalf all of the information contained in this Form 8-K that relates to such registrant and, where required, its subsidiaries. Except as stated in the preceding sentence, neither registrant is filing or furnishing any information that does not relate to such registrant, and therefore makes no representation as to any such information.

Item 2.02. Results of Operations and Financial Condition.

Item 7.01. Regulation FD Disclosure.

The following information is furnished pursuant to both Item 2.02 and 7.01.

On April 29, 2016, Pinnacle West Capital Corporation (the “Company” or “Pinnacle West”) issued a press release regarding its financial results for the fiscal quarter ended March 31, 2016 and its earnings outlook for 2016. A copy of the press release is attached hereto as Exhibit 99.1.

The Company is providing a quarterly consolidated statistical summary and a copy of the slide presentation made in connection with the quarterly earnings conference call on April 29, 2016. This information contains Company operating results for the fiscal quarter ended April 29, 2016 and is attached hereto as Exhibits 99.2 and 99.3. The statistical summary and slide presentation are concurrently being posted to the Company’s website at www.pinnaclewest.com, which also contains a glossary of relevant terms.

Item 9.01.Financial Statements and Exhibits.

(d)Exhibits

Exhibit No.	Registrant(s)	Description
99.1	Pinnacle West APS	Earnings News Release issued on April 29, 2016.
99.2	Pinnacle West APS	Pinnacle West Capital Corporation quarterly consolidated statistical summary for the three-month periods ended March 31, 2016 and 2015.
99.3	Pinnacle West APS	Pinnacle West Capital Corporation First Quarter 2016 Results slide presentation accompanying April 29, 2016 conference call.

SIGNATURES

Pursuant to the requirements of the Securities Exchange Act of 1934, each registrant has duly caused this report to be signed on its behalf by the undersigned hereunto duly authorized.

	PINNACLE WEST CAPITAL CORPORATION
	(Registrant)
Dated: April 29, 2016	By: /s/ James R. Hatfield
	James R. Hatfield
	Executive Vice President and
	Chief Financial Officer
	ARIZONA PUBLIC SERVICE COMPANY
	(Registrant)
Dated: April 29, 2016	By: /s/ James R. Hatfield
	James R. Hatfield
	Executive Vice President and
	Chief Financial Officer

Exhibit Index

Exhibit No.	Registrant(s)	Description
99.1	Pinnacle West APS	Earnings News Release issued on April 29, 2016.
99.2	Pinnacle West APS	Pinnacle West Capital Corporation quarterly consolidated statistical summary for the three-month periods ended March 31, 2016 and 2015.
99.3	Pinnacle West APS	Pinnacle West Capital Corporation First Quarter 2016 Results slide presentation accompanying April 29, 2016 conference call.

EX-99.1

FOR IMMEDIATE RELEASE		April 29, 2016
Media Contact: Analyst Contact:	Alan Bunnell, (602) 250-3376 Paul Mountain, (602) 250-4952
Website:	pinnaclewest.com

PINNACLE WEST REPORTS 2016 FIRST-QUARTER EARNINGS

• Results in line with the company’s expectations; full-year 2016 earnings guidance affirmed

• Major planned fossil power plant outages increase operations and maintenance expenses versus a year ago

• Retail sales continue to improve as Arizona’s economy continues post-recession growth

PHOENIX - Pinnacle West Capital Corp. (NYSE: PNW) today reported consolidated net income attributable to common shareholders of $4.5 million, or $0.04 per diluted share of common stock, for the quarter ended March 31, 2016. This result compares with $16.1 million, or $0.14 per diluted share, for the same period in 2015.

“Financial results were in line with our expectations, especially given the major fossil power plant overhauls and maintenance work that we had built into our budget,” said Pinnacle West Chairman, President and Chief Executive Officer Don Brandt. “We remain optimistic that we will achieve our annual targets as customer and electricity sales growth continue to rebound, along with Arizona’s improving economy.”

Brandt cited a recent study by the U.S. Census Bureau that indicates the Phoenix-metropolitan area is the third-fastest growing of the top 15 metro areas in the U.S. A second report by Arizona’s Office of Employment and Population Statistics shows the state has formally matched its pre-recession employment levels, amid expectations of continued solid growth in both population and jobs.

Looking to the immediate future, Brandt added that the company is focused on achieving constructive regulatory outcomes on a number of key energy policy issues, including Arizona’s value and cost of distributed generation proceeding, as well as the company’s upcoming rate case. “We will continue working with various stakeholders to achieve fair policies that benefit all our customers - and that help ensure a sustainable energy future for all of Arizona,” he said.

The 2016 first-quarter results comparison was adversely impacted by increased operations and maintenance expenses, which decreased results by $0.17 per share compared with the prior-year period. The expense increase was largely comprised of higher fossil plant maintenance costs as a result of more planned work being completed in the 2016 first quarter compared to the 2015 first quarter.

The above costs were partially offset by the following items:

• The effects of weather variations improved results by $0.02 per share compared to the year-ago period despite temperatures that remained less favorable than normal. While

residential heating degree-days (a measure of the effects of weather) were 57 percent higher than last year’s first quarter, heating degree-days were still 18 percent below normal 10-year averages. A contributing factor was that February 2016 was the third-mildest February in the last 20 years and the fifth-mildest over the last 40 years.

• Increased retail transmission revenue positivelyimpacted earnings by $0.02 per share.

• Higher retail electricity sales - excluding the effects of weather variations, but including the effects of customer conservation, energy efficiency programs and distributed renewable generation - improved earnings $0.01 per share. Compared to the same quarter a year ago, weather-normalized sales increased 1.3 percent (partly the result of an additional day of sales due to the leap year), while total customer growth improved 1.3 percent quarter-over-quarter.

• The net effect of miscellaneous items increased earnings $0.02 per share.

Financial Outlook

For 2016, the Company continues to expect its on-going consolidated earnings will be within a range of $3.90 to $4.10 per diluted share, on a weather-normalized basis, and to achieve a consolidated earned return on average common equity of more than 9.5 percent.

Key factors and assumptions underlying the 2016 outlook can be found in the first-quarter 2016 earnings presentation slides on the Company’s website at pinnaclewest.com/investors.

Conference Call and Webcast

Pinnacle West invites interested parties to listen to the live webcast of management’s conference call to discuss the Company’s 2016 first-quarter results, as well as recent developments, at 12 noon ET (9 a.m. AZ time) today, April 29. A replay of the webcast can be accessed at pinnaclewest.com/presentations. To access the live conference call by telephone, dial (877) 407-8035 or (201) 689-8035 for international callers. A replay of the call also will be available until 11:59 p.m. (ET), Friday, May 6, 2016, by calling (877) 660-6853 in the U.S. and Canada or (201) 612-7415 internationally and entering conference ID number 13634257.

General Information

Pinnacle West Capital Corp., an energy holding company based in Phoenix, has consolidated assets of approximately $15 billion, about 6,200 megawatts of generating capacity and 6,400 employees in Arizona and New Mexico. Through its principal subsidiary, Arizona Public Service, the Company provides retail electricity service to nearly 1.2 million Arizona homes and businesses. For more information about Pinnacle West, visit the Company’s website at pinnaclewest.com.

Dollar amounts in this news release are after income taxes. Earnings per share amounts are based on average diluted common shares outstanding. For more information on Pinnacle West’s operating statistics and earnings, please visit pinnaclewest.com/investors.

NON-GAAP FINANCIAL INFORMATION

In this press release, we refer to “on-going earnings.” On-going earnings is a “non-GAAP financial measure,” as defined in accordance with SEC rules. We believe on-going earnings provide investors with useful indicators of our results that are comparable among periods because they exclude the effects of unusual items that may occur on an irregular basis. Investors should note that these non-GAAP financial measures involve judgments by management, including whether an item is classified as an unusual item. We use on-going earnings, or similar concepts, to measure our performance internally in reports for management.

FORWARD-LOOKING STATEMENTS

This press release contains forward-looking statements based on our 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” and similar words. Because actual results may differ materially from expectations, we caution readers 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:

• our ability to manage capital expenditures and operations and maintenance costs while maintaining high reliability and customer service levels;

• variations in demand for electricity, including those due to weather, seasonality, the general economy, customer and sales growth (or decline), and the effects of energy conservation measures and distributed generation;

• 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, including those relating to environmental requirements, regulatory 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, including returns on and of debt and equity capital investment;

• our ability to meet renewable energy and energy efficiency mandates and recover related costs;

• risks inherent in the operation of nuclear facilities, including spent fuel disposal uncertainty;

• current and future economic conditions in Arizona, including in real estate markets;

• the development of new technologies which may affect electric sales or delivery;

• the cost of debt and equity capital and the ability to access capital markets when required;

• environmental and other concerns surrounding coal-fired generation, including regulation of greenhouse gas 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 land owners 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 Arizona Corporation Commission orders.

These and other factors are discussed in Risk Factors described in Part 1, Item 1A of the Pinnacle West/APS Annual Report on Form 10-K for the fiscal year ended December 31, 2015, and in Part II, Item 1A of the Pinnacle West/APS Quarterly Report on Form 10-Q for the quarter ended

March 31, 2016, which readers should review carefully before placing any reliance on our financial statements or disclosures. Neither Pinnacle West nor APS assumes any obligation to update these statements, even if our internal estimates change, except as required by law.

# # #

PINNACLE WEST CAPITAL CORPORATION

CONSOLIDATED STATEMENTS OF INCOME

(unaudited)

(dollars and shares in thousands, except per share amounts)

		THREE MONTHS ENDED MARCH 31,
		2016			2015
Operating Revenues		$	677,167		$	671,219
Operating Expenses
	Fuel and purchased power	221,285			223,237
	Operations and maintenance	243,195			214,944
	Depreciation and amortization	119,476			120,949
	Taxes other than income taxes	42,501			43,216
	Other expenses	548			1,189
	Total	627,005			603,535
Operating Income		50,162			67,684
Other Income (Deductions)
	Allowance for equity funds used during construction	10,516			9,224
	Other income	117			235
	Other expense	(4,038		)	(4,286		)
	Total	6,595			5,173
Interest Expense
	Interest charges	50,744			48,399
	Allowance for borrowed funds used during construction	(5,227		)	(4,216		)
	Total	45,517			44,183
Income Before Income Taxes		11,240			28,674
Income Taxes		1,914			7,947
Net Income		9,326			20,727
Less: Net income attributable to noncontrolling interests		4,873			4,605
Net Income Attributable To Common Shareholders		$	4,453		$	16,122
Weighted-Average Common Shares Outstanding - Basic		111,296			110,916
Weighted-Average Common Shares Outstanding - Diluted		111,847			111,377
Earnings Per Weighted-Average Common Share Outstanding
	Net income attributable to common shareholders - basic	$	0.04		$	0.15
	Net income attributable to common shareholders - diluted	$	0.04		$	0.14

EX-99.2

Last Updated 4/29/2016 Line 2016 2015 Incr (Decr) EARNINGS CONTRIBUTION BY SUBSIDIARY (Dollars in Millions) 1 Arizona Public Service 12$ 24$ (12)$ 2 El Dorado - - - 3 Parent Company (3) (3) - 4 Net Income 9 21 (12) 5 Less: Net Income Attributable to Noncontrolling Interests 5 5 - 6 Net Income Attributable to Common Shareholders 4$ 16$ (12)$ EARNINGS PER SHARE BY SUBSIDIARY - DILUTED 7 Arizona Public Service 0.11$ 0.22$ (0.11)$ 8 El Dorado - - - 9 Parent Company (0.03) (0.04) 0.01 10 Net Income 0.08 0.18 (0.10) 11 Less: Net Income Attributable to Noncontrolling Interests 0.04 0.04 - 12 Net Income Attributable to Common Shareholders 0.04$ 0.14$ (0.10)$ 13 BOOK VALUE PER SHARE 41.39$ 39.70$ 1.69$ COMMON SHARES OUTSTANDING (Thousands) 14 Average - Diluted 111,847 111,377 470 15 End of Period - Basic 111,140 110,748 392 3 Months Ended March 31, Pinnacle West Capital Corporation Quarterly Consolidated Statistical Summary Periods Ended March 31, 2016 and 2015 Page 1 of 4

Last Updated 4/29/2016 Line 2016 2015 Incr (Decr) ELECTRIC OPERATING REVENUES (Dollars in Millions) Retail 16 Residential 299$ 294$ 5$ 17 Business 341 336 5 18 Total retail 640 630 10 Wholesale revenue on delivered electricity 19 Traditional contracts 2 2 - 20 Off-system sales 18 23 (5) 21 Native load hedge liquidation - - - 22 Total wholesale 20 25 (5) 23 Transmission for others 8 8 - 24 Other miscellaneous services 9 7 2 25 Total electric operating revenues 677$ 670$ 7$ ELECTRIC SALES (GWH) Retail sales 26 Residential 2,509 2,416 93 27 Business 3,312 3,260 52 28 Total retail 5,821 5,676 145 Wholesale electricity delivered 29 Traditional contracts 17 40 (23) 30 Off-system sales 979 1,010 (31) 31 Retail load hedge management - - - 32 Total wholesale 996 1,050 (54) 33 Total electric sales 6,817 6,726 91 Pinnacle West Capital Corporation 3 Months Ended March 31, Quarterly Consolidated Statistical Summary Periods Ended March 31, 2016 and 2015 Page 2 of 4

Last Updated 4/29/2016 Line 2016 2015 Incr (Decr) AVERAGE ELECTRIC CUSTOMERS Retail customers 34 Residential 1,063,751 1,048,954 14,797 35 Business 131,162 130,152 1,010 36 Total retail 1,194,913 1,179,106 15,807 37 Wholesale customers 44 45 (1) 38 Total customers 1,194,957 1,179,151 15,806 39 Total customer growth (% over prior year) 1.3% 1.2% 0.1% RETAIL SALES (GWH) - WEATHER NORMALIZED 40 Residential 2,578 2,593 (15) 41 Business 3,293 3,201 92 42 Total 5,871 5,794 77 43 Retail sales (GWH) (% over prior year) 1.3% (0.9)% 2.2% RETAIL USAGE (KWh/Average Customer) 44 Residential 2,358 2,305 53 45 Business 25,254 25,046 208 RETAIL USAGE - WEATHER NORMALIZED (KWh/Average Customer) 46 Residential 2,424 2,472 (48) 47 Business 25,108 24,592 516 ELECTRICITY DEMAND (MW) 48 Native load peak demand 4,317 4,250 67 WEATHER INDICATORS - RESIDENTIAL Actual 49 Cooling degree-days - - - 50 Heating degree-days 396 253 143 51 Average humidity - - - 10-Year Averages 52 Cooling degree-days - - - 53 Heating degree-days 480 480 - 54 Average humidity - - - 3 Months Ended March 31, Periods Ended March 31, 2016 and 2015 Quarterly Consolidated Statistical Summary Pinnacle West Capital Corporation Page 3 of 4

Last Updated 4/29/2016 Line 2016 2015 Incr (Decr) ENERGY SOURCES (GWH) Generation production 55 Nuclear 2,545 2,510 35 56 Coal 1,302 2,274 (972) 57 Gas, oil and other 1,869 992 877 58 Total generation production 5,716 5,776 (60) Purchased power 59 Firm load 1,330 1,256 74 60 Marketing and trading 76 83 (7) 61 Total purchased power 1,406 1,339 67 62 Total energy sources 7,122 7,115 7 POWER PLANT PERFORMANCE Capacity Factors 63 Nuclear 101% 101% - 64 Coal 35% 54% (19)% 65 Gas, oil and other 25% 18% 7% 66 System average 42% 42% - ECONOMIC INDICATORS Building Permits (a) 67 Metro Phoenix 5,285 4,463 822 Arizona Job Growth (b) 68 Payroll job growth (% over prior year) 3.0% 2.4% 0.6% 69 Unemployment rate (%, seasonally adjusted) 5.5% 6.3% (0.8)% Sources: (a) U.S. Census Bureau (b) Arizona Department of Economic Security 3 Months Ended March 31, Pinnacle West Capital Corporation Quarterly Consolidated Statistical Summary Periods Ended March 31, 2016 and 2015 Page 4 of 4

EX-99.3

First Quarter 2016 FIRST QUARTER 2016 RESULTS April 29, 2016

First Quarter 20162 FORWARD LOOKING STATEMENTS AND NON-GAAP FINANCIAL MEASURES 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” 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: our ability to manage capital expenditures and operations and maintenance costs while maintaining high reliability and customer service levels; variations in demand for electricity, including those due to weather seasonality, the general economy, customer and sales growth (or decline), and the effects of energy conservation measures and distributed generation; power plant and transmission system performance and outages; competition in retail and wholesale power markets; regulatory and judicial decisions, developments and proceedings; new legislation, ballet initiatives and regulation, including those relating to environmental requirements, regulatory 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, including returns on and of debt and equity capital investments; our ability to meet renewable energy and energy efficiency mandates and recover related costs; risks inherent in the operation of nuclear facilities, including spent fuel disposal uncertainty; current and future economic conditions in Arizona, including in real estate markets; the development of new technologies which may affect electric sales or delivery; the cost of debt and equity capital and the ability to access capital markets when required; environmental and other concerns surrounding coal-fired generation, including regulation of greenhouse gas 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 land owners 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 Risk Factors described in Part I, Item 1A of the Pinnacle West/APS Annual Report on Form 10-K for the fiscal year ended December 31, 2015, and in Part II, Item 1A of the Pinnacle West/APS Quarterly Report on Form 10-Q for the quarter ended March 31, 2016, 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. We present “gross margin” per diluted share of common stock. Gross margin refers to operating revenues less fuel and purchased power expenses. Gross margin is a “non-GAAP financial measure,” as defined in accordance with SEC rules. The appendix contains a reconciliation of this non-GAAP financial measure to the referenced revenue and expense line items on our Consolidated Statements of Income, which are the most directly comparable financial measures calculated and presented in accordance with generally accepted accounting principles in the United States of America (GAAP). We view gross margin as an important performance measure of the core profitability of our operations. We refer to “on-going earnings” in this presentation, which is also a non-GAAP financial measure. We believe on-going earnings provide investors with a useful indicator of our results that is comparable among periods because it excludes the effects of unusual items that may occur on an irregular basis. Investors should note that these non-GAAP financial measures may involve judgments by management, including whether an item is classified as an unusual item. These measures are key components of our internal financial reporting and are used by our management in analyzing the operations of our business. We believe that investors benefit from having access to the same financial measures that management uses.

First Quarter 20163 Gross Margin(1) $0.07 ON-GOING EPS VARIANCES 1ST QUARTER 2016 VS. 1ST QUARTER 2015 Other, net $(0.01) D&A $0.01 (1) Excludes costs, and offsetting operating revenues, associated with renewable energy (excluding AZ Sun) and demand side management programs. O&M (1) $(0.17) 1Q 2015 1Q 2016 Gross Margin Weather $0.02 Transmission $0.02 kWh Sales $0.01 AZ Sun $0.01 Other, net $0.01 $0.14 $0.04

First Quarter 20164 ECONOMIC INDICATORS Arizona and Metro Phoenix remain attractive places to live and do business Single Family & Multifamily Housing Permits Maricopa County Job Growth (Total Nonfarm) – Metro Phoenix 0.0% 2.5% 5.0% '11 '12 '13 '14 '15 '16 Metro Phoenix U.S. YoY Change Construction, business services, financial services and healthcare adding jobs at a rate above 4% Phoenix ranked 1st in tech industry job growth over last 2 years (tied with San Francisco) - CBRE September 2015 Phoenix ranked 6th for commercial real estate investment (3rd excluding Texas cities) - Situs RERC, August 2015 Arizona ranked 1st for projected job growth - Forbes September 2015 E 0 10,000 20,000 30,000 40,000 '07 '08 '09 '10 '11 '12 '13 '14 '15 '16 Single Family Multifamily Q1 Metro Phoenix growth rate 3rd fastest among top 15 metro areas - U.S. Census Bureau March 2016

First Quarter 20165 2016 ON-GOING EPS GUIDANCE Key Factors & Assumptions as of April 29, 2016 2016 Electricity gross margin* (operating revenues, net of fuel and purchased power expenses) $2.34 – $2.39 billion • Retail customer growth about 1.5-2.5% • Weather-normalized retail electricity sales volume about 0-1.0% to prior year taking into account effects of customer conservation, energy efficiency and distributed renewable generation initiatives • Assumes normal weather Operating and maintenance* $825 - $845 million Other operating expenses (depreciation and amortization including impacts related to Palo Verde sale leaseback, and taxes other than income taxes) $645 - $665 million Interest expense, net of allowance for borrowed and equity funds used during construction (Total AFUDC $50 million) $155 - $165 million Net income attributable to noncontrolling interests ~$20 million Effective tax rate 34-35% Average diluted common shares outstanding ~112.0 million On-Going EPS Guidance $3.90 - $4.10 * Excludes O&M of $97 million, and offsetting revenues, associated with renewable energy and demand side management programs.

First Quarter 2016 APPENDIX

First Quarter 20167 2016 KEY DATES ACC Key Dates Docket # Q1 Q2 Q3 Q4 Key Recurring Regulatory Filings Lost Fixed Cost Recovery E-01345A-11-0224 Jan 15 Transmission Cost Adjustor E-01345A-11-0224 May 15 Renewable Energy Surcharge TBD Jul 1 APS Rate Case E-01345A-16-0036 Jun 1: Initial filing TBD TBD Resource Planning and Procurement E-00000V-15-0094 Mar 1: Preliminary IRP filed Oct 1: File updates to preliminary IRP* Value and Cost of Distributed Generation E-00000J- 14-0023 Feb 25: DG Methodologies & supporting testimony filed Apr 7: Rebuttal testimony and alternate proposals due Apr 15: Pre-hearing Apr 18: Hearing, to be completed by May 6 ACC Open Meetings - ACC Open Meetings Held Monthly * April 2017: Final IRP due Other Key Dates Docket # Q1 Q2 Q3 Q4 Arizona State Legislature n/a In session Jan 11- End of Q2 Elections n/a Aug 30: Primary Nov 8: General All Source Request for Proposal (RFP) n/a Mar 11: RFP Issued Jun 9: Responses Due

First Quarter 20168 ARIZONA ELECTRIC UTILITIES GENERAL RATE CASES UNS Electric Docket # E-04204A-15-0142 Application filed May 5, 2015 Direct testimony - ex rate design, cost of service (Nov 6, 2015) Direct testimony - rate design, cost of service (Dec 9, 2015) Rebuttal testimony (Jan 19, 2016) Surrebuttal testimony (Feb 23, 2016) Rejoinder testimony (Feb 29, 2016) Pre-hearing (Feb 26, 2016) Hearing (Mar 1, 2016) Post hearing initial briefs (April 25, 2016) Reply briefs (May 11, 2016) Tucson Electric Power Company Docket # E-01933A-15-0322 Application filed Sep 4, 2015 Direct testimony – ex rate design and cost of service (Jun 3, 2016) Direct testimony – rate design and cost of service (Jun 24, 2016) Rebuttal testimony (Jul 25, 2016) Surrebuttal testimony (Aug 18, 2016) Rejoinder testimony (Aug 25, 2016) Pre-hearing (Aug 25, 2016) Hearing (Aug 31, 2016) Sulphur Springs Valley Electric Cooperative Docket # E-01575A-15-0312 Application filed Aug 31, 2015 Direct testimony - ex rate design, cost of service (Mar 18, 2016) Direct testimony - rate design, cost of service (Apr 1, 2016) Rebuttal testimony (Apr 15, 2016) Surrebuttal testimony (May 4, 2016) Rejoinder (May 11, 2016) Pre-hearing (May 13, 2016) Hearing (May 17, 2016) Settlement discussions began April 15, 2016 Trico Electric Cooperative Docket # E-01461A-15-0363 Application filed Oct 23, 2015 Direct testimony - ex rate design, cost of service (May 4, 2016) Direct testimony - rate design, cost of service (May 25, 2016) Rebuttal testimony (Jun 22, 2016) Surrebuttal testimony (Jul 8, 2016) Rejoinder (Jul 15, 2016) Pre-hearing (Jul 18, 2016) Hearing (Jul 19, 2016)

First Quarter 20169 FINANCIAL OUTLOOK Key Factors & Assumptions as of April 29, 2016 Assumption Impact Retail customer growth • Expected to average about 2-3% annually • Modestly improving Arizona and U.S. economic conditions Weather-normalized retail electricity sales volume growth • About 0.5-1.5% after customer conservation and energy efficiency and distributed renewable generation initiatives Assumption Impact AZ Sun Program • Additions to flow through RES until next base rate case • First 50 MW of AZ Sun is recovered through base rates Lost Fixed Cost Recovery (LFCR) • Offsets 30-40% of revenues lost due to ACC-mandated energy efficiency and distributed renewable generation initiatives Environmental Improvement Surcharge (EIS) • Assumed to recover up to $5 million annually of carrying costs for government- mandated environmental capital expenditures Power Supply Adjustor (PSA) • 100% recovery as of July 1, 2012 Transmission Cost Adjustor (TCA) • TCA is filed each May and automatically goes into rates effective June 1 • Beginning July 1, 2012 following conclusion of the regulatory settlement, transmission revenue is accrued each month as it is earned. Four Corners Acquisition • Four Corners rate increase effective January 1, 2015 Potential Property Tax Deferrals (2012 retail rate settlement): Assume 60% of property tax increases relate to tax rates, therefore, will be eligible for deferrals (Deferral rates: 50% in 2013; 75% in 2014 and thereafter) Gross Margin – Customer Growth and Weather (2016-2018) Gross Margin – Related to 2012 Retail Rate Settlement Outlook Through 2016: Goal of earning more than 9.5% Return on Equity (earned Return on Equity based on average Total Shareholder’s Equity for PNW consolidated, weather-normalized)

First Quarter 201610 RATE BASE APS’s revenues come from a regulated retail rate base and meaningful transmission business $6.0 $6.2 $7.4 $1.3 $1.5 $1.8 2014 2015 2016 2017 2018 APS Rate Base Growth Year-End ACC FERC Total Approved Rate Base Projected Most Recent Rate Decisions ACC FERC Rate Effective Date 7/1/2012 6/1/2015 Test Year Ended 12/31/2010* 12/31/2014 Rate Base $5.7B $1.3B Equity Layer 54% 58% Allowed ROE 10.00% 10.75% *Adjusted to include post test-year plant in service through 3/31/2012 83% 17% Generation & Distribution Transmission Rate base $ in billions, rounded

First Quarter 201611 Credit Ratings • A- rating or better at S&P, Moody’s and Fitch 2016 Major Financing Activities • $100 million term loan closed April 2016 • Currently expect up to $550 million of long-term debt, including: – Issuance to refinance $250 million of debt maturing in August • In addition, there will be several tax-exempt series remarketed or refinanced We are disclosing credit ratings to enhance understanding of our sources of liquidity and the effects of our ratings on our costs of funds. BALANCE SHEET STRENGTH $250 $50 $600 $250 $125 $- $100 $200 $300 $400 $500 $600 2016 2017 2018 2019 2020 APS PNW ($Millions) Debt Maturity Schedule

First Quarter 201612 OPERATIONS & MAINTENANCE OUTLOOK Goal is to keep O&M per kWh flat, adjusted for planned outages $754 $761 $788 $805 $772 $150 $124 $137 $103 $96 $97 2011 2012 2013 2014 2015 2016E PNW Consolidated RES/DSM* *Renewable energy and demand side management expenses are offset by adjustor mechanisms. ($ Millions) $825 - $845

First Quarter 201613 $263 $220 $218 $298 $66 $77 $234 $115 $44 $232 $194 $90 $58 $110 $1 $1 $201 $114 $200 $150 $340 $364 $354 $382 $85 $88 $84 $88 2015 2016 2017 2018 CAPITAL EXPENDITURES Capital expenditures are funded primarily through internally generated cash flow ($ Millions) $1,205 $1,285 Other Distribution Transmission Renewable Generation Environmental1 Traditional Generation Projected $1,124 New Gas Generation2 $1,057 • The table does not include capital expenditures related to El Paso's 7% interest in Four Corners Units 4 and 5 of $3 million in 2015, $30 million in 2016 and $25 million in 2017. • 2016 – 2018 as disclosed in First Quarter 2016 Form 10-Q. 1 Includes Selective Catalytic Reduction controls at Four Corners with in-service dates of Q4 2017 (Unit 5) and Q1 2018 (Unit 4) 2 Ocotillo Modernization Project: 2 units scheduled for completion in Q4 2018, 3 units schedule for completion in Q1 2019

First Quarter 201614 249 357 339 442 610 710 641 785 871 939 523 837 499 699 845 730 1179 1207 1433 1219 1097 1306 1188 1261 1309 902 1466 0 250 500 750 1000 1250 1500 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec 2014 Applications 2015 Applications 2016 Applications * As of March 31, 2016, over 40,000 residential grid-tied solar photovoltaic (PV) systems have been installed in APS’s service territory. Excludes APS Solar Partner Program residential PV systems. Note: www.arizonagoessolar.org logs total residential application volume, including cancellations. Solar water heaters can also be found on the site, but are not included in the chart above. RESIDENTIAL PV APPLICATIONS* 15 19 23 44 51 57 74 2009 2011 2013 2015 Residential DG (MW) Annual Additions

First Quarter 201615 (8) (6) 2 5 (5) $(20) $(15) $(10) $(5) $0 $5 Q1 Q2 Q3 Q4 Q1 GROSS MARGIN EFFECTS OF WEATHER VARIANCES VS. NORMAL Pretax Millions All periods recalculated to current 10-year rolling average (2005-2014) 2015 $(7) Million 2016 $(5) Million

First Quarter 201616 12 7 11 11 8 11 14 18 12 12 $0 $10 $20 $30 $40 Q1 Q2 Q3 Q4 Q1 Renewable Energy Demand Side Management RENEWABLE ENERGY AND DEMAND SIDE MANAGEMENT EXPENSES* * O&M expenses related to renewable energy and demand side management programs are partially offset by comparable revenue amounts Pretax Millions 2015 $96 Million 2016 $20 Million

First Quarter 201617 NON-GAAP MEASURE RECONCILIATION GROSS MARGIN $ millions pretax, except per share amounts 2016 2015 Operating revenues* 677$ 671$ Fuel and purchased power expenses* (221) (223) Gross margin 456 448 0.04$ Adjustments: Renewable energy (excluding AZ Sun), demand side management and similar regulatory programs (14) (19) 0.03 Gross margin - adjusted 442$ 429$ 0.07$ * Line items from Consolidated Statements of Income Three Months Ended March 31, EPS Impact