WAL Western Alliance Bancorporation

Proposal No. 3 – Ratification of Auditor.

The proposal to ratify the appointment of RSM US LLP as the Company’s independent auditor will be approved if a majority in voting power of the shares present in person or represented by proxy and entitled to vote cast their votes for the proposal. If the appointment is not approved by the stockholders, the adverse vote will be considered a direction to the Audit Committee to consider other auditors for next year. However, because of the difficulty in making any substitution of auditors so long after the beginning of the current year, the appointment in 2017 will stand, unless the Audit Committee finds other good reason for making a change.

The management and Board of Directors of the Company know of no other matters to be brought before the meeting. If other matters are properly presented to the stockholders for action at the meeting or any adjournments or postponements thereof, it is the intention of the proxy holders named in the proxy to vote in their discretion on all matters on which the shares of common stock represented by such proxy are entitled to vote.

Shares in the Company 401(k) Plan

If you hold shares in the Western Alliance Bancorporation 401(k) Plan (the “401(k) Plan”), you may instruct the plan trustee on how to vote your shares in the 401(k) Plan by mail, by telephone or over the internet as described above. You may vote or provide instructions with respect to all of the shares of our common stock allocated to your account on the Record Date.

In addition, your vote or instructions will also apply pro rata , along with the votes or instructions of other participants in the 401(k) Plan who return voting instructions to the trustee, to all shares held in the 401(k) Plan for which voting directions are not received. These undirected shares may include shares credited to the accounts of participants who do not return their voting instructions and shares held in the 401(k) Plan that were not credited to individual participants’ accounts as of the Record Date. The trustee will automatically apply your voting preference to the undirected shares proportionately with all other participants who provide voting directions.

Corporate Governance

The Board of Directors is responsible for ensuring effective governance over the Company’s affairs. The Company has adopted Corporate Governance Guidelines and a Code of Business Conduct and Ethics. These documents are available in the Governance Documents section of the Investor Relations page of the Company’s website at www.westernalliancebancorporation.com or, for print copies, by writing to the Company at One E. Washington Street, Suite 1400, Phoenix, Arizona 85004, Attention: Corporate Secretary.

Board Leadership Structure

In accordance with the Company’s Bylaws, as amended (“Bylaws”), the Chairman of the Board of Directors (the “Chairman”) is a discretionary position whose sole stated duty is to preside at meetings of the Board of Directors and meetings of stockholders, as well as to perform such other duties as assigned to him by the Board of Directors. The Chief Executive Officer (“CEO”) is required to be a member of the Board of Directors, subject to the direction of the Board of Directors, and has general supervision, direction and control of the business and officers of the Company. The positions of Chairman and CEO may be held by the same person or may be held by two people. The Board of Directors does not have a definitive policy on whether the role of the Chairman and the CEO should be separate.

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CORPORATE GOVERNANCE  •  BOARD LEADERSHIP STRUCTURE

The Company has a Lead Independent Director, who is selected by the non-management directors, because the Board of Directors believes the position can contribute to improved corporate performance in the following ways: (1) supporting effective communication and building a productive relationship between the CEO and other members of executive management and the Board of Directors; (2) leading the process for improving performance of the Board of Directors; and (3) assisting in a crisis. Mr. Beach has served as the Company’s Lead Independent Director since 2010. In addition to the duties of all directors, the specific responsibilities of the Company’s Lead Independent Director are as follows:

After careful consideration, the Nominating and Corporate Governance Committee (“Governance Committee”) continues to believe that the Company’s current structure of the Board of Directors combining the CEO and Chairman positions and utilizing a Lead Independent Director is the most appropriate leadership structure for the Company and its stockholders. The Governance Committee based its determination on a number of reasons, the most significant of which include the following:

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CORPORATE GOVERNANCE  •  DIRECTOR SELECTION PROCESS

Director Selection Process

One of the primary responsibilities of the Governance Committee is to assist the Board of Directors in identifying, and reviewing the qualifications of, prospective directors of the Company. The Board of Directors and the Governance Committee periodically review the appropriate size and composition of the Board of Directors. In considering candidates for the Board of Directors, the Governance Committee considers the entirety of each candidate’s credentials and does not have any specific minimum qualifications that must be met by a Governance Committee-recommended nominee.

The Governance Committee does not assign specific weights to particular criteria and no particular criterion is necessarily applicable to all prospective nominees. In 2017, the Governance Committee adopted a Director’s Skills & Experience Matrix, which, in addition to the criteria set forth above, the Governance Committee uses to consider how the skills and attributes of each individual candidate or incumbent director work together to create a board that is collegial, engaged and effective in performing its duties. Moreover, the Governance Committee believes that the background and qualifications of the directors, considered as a group, should provide a significant mix of experience, knowledge and abilities that will allow the Board of Directors to fulfill its responsibilities.

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CORPORATE GOVERNANCE  •  BOARD COMPOSITION

The Governance Committee will consider nominees for directors recommended by stockholders. A stockholder wishing to recommend a director candidate for consideration by the Committee should send such recommendation to the Company’s Corporate Secretary at the address shown on the cover page of this proxy statement, who will then forward it to the Governance Committee. Any such recommendation should include the following minimum information for each director nominee: full name, address and telephone number, age, a description of the candidate’s qualifications for service on the Board of Directors (such as principal occupation and directorships on publicly-held companies during the past five years), the candidate’s written consent to be considered for nomination and to serve if nominated and elected, and the number of shares of Company common stock owned, if any. A stockholder who wishes to nominate an individual as a director candidate at the annual meeting of stockholders, rather than recommend the individual to the Governance Committee as a nominee, must comply with certain advance notice requirements. See “ Stockholder Proposals for the 2018 Annual Meeting ” on page 55 for more information on these procedures.

If the Governance Committee receives a director nomination from a stockholder or group of stockholders who (individually or in the aggregate) beneficially own greater than 5% of the Company’s outstanding voting stock for at least one year as of the date of such recommendation, the Company, as required by applicable securities law, will identify the candidate and stockholder or group of stockholders recommending the candidate and will disclose in its proxy statement whether the Governance Committee chose to nominate the candidate, as well as certain other information.

In addition to potential director nominees submitted by stockholders, the Governance Committee considers candidates submitted by directors, as well as self-nominations by directors and, from time to time, it may consider candidates submitted by a third-party search firm hired for the purpose of identifying director candidates. The Governance Committee conducts an independent due diligence process to review potential director candidates and their individual qualifications, and all such candidates, including those submitted by stockholders, will be similarly evaluated by the Governance Committee using the Board of Directors membership criteria described above.

All of the nominees standing for election to the Company’s Board of Directors at this year’s Annual Meeting are current directors. The Governance Committee and the Board of Directors believe that all the nominees satisfy the above described director standards. Accordingly, all of such nominees were approved for re-election by the Board of Directors, based in part on the recommendation of the Governance Committee. With respect to this year’s Annual Meeting, no nominations for directors were received from stockholders.

Board Composition

The Company’s Bylaws provide that the Board of Directors will consist of not less than eight or more than seventeen directors. The Board of Directors may, from time to time, fix the number of directors within these limits. Neither M. Nafees Nagy, M.D. nor John Peter Sande III, each current directors of the Company, have been nominated for re-election to the Board of Directors at the Company’s 2017 Annual Meeting. Accordingly, effective as of the date of the Annual Meeting, the Board of Directors has reduced the number of directors from sixteen to fourteen. At the Annual Meeting, the fourteen directors described in the “ Information as to Director Nominees ” section will be elected to serve for one-year terms.

At each annual meeting of stockholders, the successors to directors whose terms will then expire will be elected to serve from the time of election and qualification until the annual stockholders’ meeting following election. The number of directors may be changed only by resolution of the Board of Directors.

Information regarding each of the Company’s directors is set forth below. All ages are provided as of December 31, 2016.

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CORPORATE GOVERNANCE  •  BOARD COMPOSITION

Information as to Director Nominees

The terms of the following directors will expire at this year’s Annual Meeting. The Board of Directors has nominated the individuals listed below, all of whom are current directors of the Company, to be elected as directors at the Annual Meeting. See “ Items of Business To Be Acted On At The Meeting – Proposal No.  1 Election of Directors ” on page 51.

Mr. Beach has been a director of the Company since April 2005 and Lead Independent Director since January 2010. He served as Chairman of the Company’s Audit Committee from May 2009 to March 2017. Mr. Beach was a director of Western Alliance Bank since its formation until December 2015 and was reappointed as a director of Western Alliance Bank in March 2017. Mr. Beach has been the Chairman of BeachFleischman PC, an accounting and business advisory firm in Southern Arizona, since May 1991, and served as its Chief Executive Officer from 1991 to 2015. Mr. Beach is a certified public accountant, received a BS in business administration and an MBA from the University of Arizona, and has 43 years of experience in public accounting. Mr. Beach was the Vice-Chairman of Carondelet Health Network, one of the largest hospital systems in Southern Arizona, from July 2004 until December 2007, and served as the chairman of its Audit Committee from July 2003 until December 2007. Mr. Beach served a term as Chairman of Carondelet Health Network in 2008, and retired from the Carondelet board of directors on December 31, 2008. Mr. Beach’s experience as an accounting professional and his background as an executive and director contribute management and financial expertise to our Board of Directors, as well as leadership skills and significant knowledge of the Southern Arizona business environment.

Mr. Boyd has been a director and stockholder of the Company since 2002 and was a founder of its first bank subsidiary, Bank of Nevada. Mr. Boyd was appointed as a director of Western Alliance Bank in March 2017. Mr. Boyd has served as a director of Boyd Gaming Corporation since its inception in June 1988, and as Chairman of the Board of Directors since August 1988. Mr. Boyd also held the position of CEO of Boyd Gaming Corporation from August 1988 through December 2007, when he was elected to the Office of Executive Chairman of that company, effective January 2008. Mr. Boyd has been a director of California Hotel and Casino since its inception in 1973. He has previously served on the board of directors and for the past fifteen years has been the President Emeritus of the National Center for Responsible Gaming. He served as a director of Nevada State Bank from 1965 to 1985. Mr. Boyd played a leading role in founding the William S. Boyd School of Law at the University of Nevada, Las Vegas. Mr. Boyd is the father of director Marianne Boyd Johnson. Mr. Boyd brings extensive experience in executive and operational management to our Board of Directors, as well as experience in a highly regulated industry. He is the Chairman and former CEO of Boyd Gaming, a NYSE-listed public company, and a prominent fixture within the Las Vegas business community where the Company’s Bank of Nevada division operates. Additionally, Mr. Boyd has a law degree and actively practiced in Las Vegas for 15 years, specializing in business related matters. He also has over 20 years of previous experience as a bank board director.

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CORPORATE GOVERNANCE  •  BOARD COMPOSITION

Mr. Gould has been a director of the Company since October 2015 and was previously a director of Bridge Capital Holdings from 2009 until it merged into the Company in June of 2015. Mr. Gould was appointed as a director of Western Alliance Bank in March 2017. Mr. Gould is Vice Chairman of Carpenter and Company and is a managing member of Carpenter Fund Manager, GP, LLC, the general partner of the Carpenter Community BancFunds. From 2004 to 2005, Mr. Gould was California Commissioner of Financial Institutions under Governor Arnold Schwarzenegger. From 2002 to 2003, he was Vice Chairman of The Bank of the West, which had acquired United California Bank where he was Vice Chairman and Chief Operating Officer of the bank from 1992 to 2002. Prior to that position he was Managing Partner of The Secura Group. He was State Superintendent of Banks for the State of California under Governor George Deukmejian. Mr. Gould also served as an officer at Bank of America and Wells Fargo Bank. Mr. Gould’s experience in management at large financial institutions and as the Commissioner of California’s bank regulatory agency enables him to provide valuable insights to our Board of Directors concerning bank industry, management and regulatory matters.

Mr. Hilton has been a director of the Company since December 2002 and was a director of Western Alliance Bank from February 2003 until it merged with Bank of Nevada and Torrey Pines Bank in December 2013 and was reappointed as a director of Western Alliance Bank in March 2017. Mr. Hilton was the co-founder and is the Chairman and Chief Executive Officer of Meritage Homes Corporation. Mr. Hilton founded Arizona-based Monterey Homes in 1985. Under Mr. Hilton’s leadership, Monterey became a publicly-traded company and combined with Legacy Homes in 1997, resulting in the creation of Meritage Homes Corporation. Mr. Hilton received his Bachelor of Science degree in accounting from the University of Arizona. Mr. Hilton contributes considerable knowledge of the southwestern real estate market to our Board of Directors. As the Chairman and CEO of another NYSE-listed public company, Mr. Hilton also brings executive management experience, risk assessment skills and public company expertise to our Board of Directors.

Ms. Johnson has been a director of the Company since inception and was a founding director of its first bank subsidiary, Bank of Nevada. Ms. Johnson was appointed as a director of Western Alliance Bank in March 2017. Since 1992, Ms. Johnson has been a member of the board of directors of Boyd Gaming Corporation and has served as its Vice Chairman of the Board since February 2001. Ms. Johnson was Senior Vice President of Boyd Gaming from December 2001 until December 2007, and she was promoted to Executive Vice President in January 2008. Ms. Johnson has served Boyd Gaming since 1977 in a variety of capacities, including sales and marketing. Ms. Johnson served as a director of Nevada Community Bank until its sale to First Security Bank (Wells Fargo) in 1993. Ms. Johnson is the daughter of director William S. Boyd. Ms. Johnson brings to our Board of Directors nearly two decades of experience in both the banking and highly regulated gaming industry, as well as extensive knowledge of the Las Vegas, Nevada market, and considerable public company experience.

Mr. Latta has been a director of the Company since 2015 and was previously a director of Bridge Capital Holdings from 2004 until it merged into the Company in June of 2015. Mr. Latta was appointed as a director of Western Alliance Bank in March 2017. Mr. Latta is a senior partner at Wilson Sonsini Goodrich & Rosati, one of the nation’s leading technology and growth business law firms, where he has worked since 1979 and has served as a member of various firm management committees. Mr. Latta has substantial experience in a broad range of general corporate and transactional matters, including company formations, venture capital financings, public offerings, and mergers and acquisitions. Mr. Latta brings corporate finance experience and familiarity with corporate governance matters to our Board of Directors, as well as Audit Committee and Compensation Committee experience.

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CORPORATE GOVERNANCE  •  BOARD COMPOSITION

Mr. Mack has been a director of the Company since April 2005. Mr. Mack was a director of Torrey Pines Bank from its formation in May 2003 until it merged with Western Alliance Bank in December 2013, was Chairman of Torrey Pines Bank from July 2009 to December 2013, and was a director of Western Alliance Bank from December 2013 to December 2015 and was reappointed as a director of Western Alliance Bank in March 2017. Mr. Mack has held licenses in the State of California as a certified public accountant, attorney and real estate broker. Mr. Mack co-manages Southwest Value Partners Enterprise, a private real estate investment firm located in San Diego, California (“SVP”). Mr. Mack’s legal and accounting experience, his involvement in auditing practices and risk management programs and policies, and his knowledge of the investment and real estate markets provide the Board of Directors with invaluable expertise in these areas.

Mr. Marshall has been a director of the Company since inception and was a founding director of its first bank subsidiary, Bank of Nevada. Mr. Marshall was also a director of Torrey Pines Bank from January 2011 until it merged into Western Alliance Bank in December 2013. Mr. Marshall was appointed as a director of Western Alliance Bank in March 2017. Mr. Marshall was a director of Marshall Retail Group from May 1976 to 2015, served as its Chief Executive Officer until January 2005 and served as Chairman until 2014. The Marshall Retail Group owns and operates stores in more than 140 locations, primarily in major casino-hotels in Nevada, Mississippi and New Jersey. He is currently the owner and President of Marshall Management Co., a real estate investment and property management company in Las Vegas and serves on the board of Sourcing Network International, LLC. Mr. Marshall served on the board of directors of Consumer Health Services from July 2007 until July 2012, and as its Chief Operating Officer from March 2011 until March 2012. Mr. Marshall’s long history with the Company, his extensive leadership experience and knowledge of the Las Vegas retail market and community provide our Board of Directors with an important perspective for assessing and managing risks and planning for corporate strategy in one of its largest markets. Mr. Marshall also brings to our Board of Directors his experience in the highly regulated gaming industry and marketing and branding expertise.

Dr. Nave has served as a director of the Company since its establishment in 1995, and served as a director of Bank of Nevada from 1994 until it merged into Western Alliance Bank in December 2013. Dr. Nave was appointed as a director of Western Alliance Bank in March 2017. Dr. Nave, a former officer in the armed forces, has owned the Tropicana Animal Hospital since 1974, and is the owner of multiple veterinary hospitals. In July 2013, he finished his second six-year term as the Director of International Affairs for the American Veterinary Medical Association, and is a past President of that organization. He is a member and past President of the Nevada Veterinary Medical Association and the Western Veterinary Conference, as well as a member of the Clark County Veterinary Medical Association, the National Academy of Practitioners, and the American Animal Hospital Association. He has previously served as the Globalization Liaison Agent for Education and Licensing for the American Veterinary Medical Association, and as a member of the Executive Board of the World Veterinary Association. Dr. Nave was also the Chairman of the University of Missouri, College of Veterinary Medicine Development Committee. He was a member of the Nevada State Athletic Commission from 1988 to 1999 and served as its Chairman from 1989 to 1992 and from 1994 to 1996. Dr. Nave serves as an independent director of Station Casinos, LLC and is chairman of its Audit Committee. He also serves as lead director, Chairman of the Audit Committee, and as a member of the Governance and Compensation Committees for Red Rock Resorts, Inc. Dr. Nave’s management skills, leadership experience, financial acumen and Audit Committee experience add an important dimension to the composition of our Board of Directors.

Mr. Patriarca has been a director of the Company since September 2016 and Chairman of the Company’s Audit Committee since March 2017. Mr. Patriarca was appointed as a director of Western Alliance Bank in March 2017. Mr. Patriarca advised large financial institutions on risk management, audit, compliance, governance and a broad range of regulatory issues at Promontory Financial Group, a premier financial services consulting firm, serving as Managing Director from 2009 through 2014 and as a consultant from 2005 through 2008. From 1999 through 2005, Mr. Patriarca served as the global head of risk management and audit at Visa International and in several executive positions, including General Auditor, at Wells Fargo Bank from 1992 through 1999. Prior to his 23 years of private sector experience, Mr. Patriarca performed senior regulatory roles at the Office of the Comptroller of the Currency and the Office of Thrift Supervision over 16 years of government service. Mr. Patriarca is a career financial services executive with deep and diverse experience.

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CORPORATE GOVERNANCE  •  BOARD COMPOSITION

Mr. Sarver has been the Chairman and Chief Executive Officer of the Company since December 2002. He also served as the President of the Company from December 2002 to April 2010. He served on the Torrey Pines Bank board of directors until the bank merged with Western Alliance Bank in December 2013. He currently serves on the board of directors of Western Alliance Bank and was appointed Chairman in January 2016. Mr. Sarver organized and founded National Bank of Arizona in 1984 and served as President at the time of the sale of that bank in 1994 to Zions Bancorporation. Mr. Sarver was the lead investor and CEO of GB Bancorporation, the former parent company of Grossmont Bank, from 1995 to 1997. Mr. Sarver served as Chairman and CEO of California Bank and Trust and as an Executive Vice President with Zions Bancorporation from June 1998 to March 2001. He served as a director and credit committee member of Zions Bancorporation from 1995 to 2001, and as a director of Skywest Airlines from 2000 to 2015. Mr. Sarver was an original founder and managing principal of Southwest Value Partners Enterprises (“SVP”), but no longer serves in a managing or controlling capacity. Mr. Sarver is a member of SVP’s three-person underwriting committee. Mr. Sarver is also a director of Meritage Homes Corporation, the Managing Partner of the Phoenix Suns NBA basketball team, a member of the board of directors of the Sarver Heart Center at the University of Arizona, and a part owner of the Spanish professional soccer club Real Club Deportivo Mallorca, S.A.D. Mr. Sarver brings extensive experience in banking, real estate and executive management to our Board. Mr. Sarver’s experience as a leader and entrepreneur in the Southwest, where the Company operates, provides insight to the Board of Directors on the factors that impact both the Company and the communities in which it operates. Moreover, Mr. Sarver’s day-to-day leadership and intimate knowledge of the Company’s business and operations provide our Board of Directors with Company-specific experience and expertise.

Mr. Snyder has served as a director of the Company since 1997 and served as a director of Western Alliance Bank from January 2014 to December 2015 and was reappointed as a director of Western Alliance Bank in March 2017. Mr. Snyder was a director of Bank of Nevada from 1997 until it merged with Western Alliance Bank in December 2013, and served as Chairman of Bank of Nevada from January 2010 to December 2013. He was a founding director of the entity created to charter Bank of Nevada and was one of its initial investors. Mr. Snyder has served in senior leadership positions at University of Nevada, Las Vegas (UNLV) since June 2010. He was Dean of the William F. Harrah College of Hotel Administration from June 2010 to June 2013; Executive Dean for Strategic Development from June 2013 to January 2014; President from February 2014 to January 2015 while the university conducted a national search to fill the vacancy created by the unexpected resignation of the former President; and served as Presidential Advisor for Strategic Initiatives from January 2015 to January 2016. Mr. Snyder continues to serve as a Presidential Advisor in a voluntary capacity for UNLV. He is also Chairman of The Smith Center for the Performing Arts, and is a director of Tutor Perini Corporation and Switch Ltd. Mr. Snyder served as a director of NV Energy from 2005 to 2013. Mr. Snyder was the President of Boyd Gaming Corporation from January 1997 to March 2005, having joined the company’s board of directors in April 1996 and its management team in July 1996. Prior to that, he was President and CEO of the Fremont Street Experience LLC, a private/public partnership formed to develop and operate a major redevelopment project in Downtown Las Vegas. Mr. Snyder was previously Chairman of the board of directors and CEO of First Interstate Bank of Nevada, then Nevada’s largest full-service bank, from 1987 through 1991. During his 22 years with First Interstate Bank from 1969 to 1991, Mr. Snyder served in various management positions in retail and corporate banking, as well as international and real estate banking. He has served and continues to serve on the boards of numerous industry and community organizations. Mr. Snyder brings to our Board of Directors an extraordinary understanding of the Company’s business, history and organization as well as extensive leadership skills, banking and regulatory expertise and management experience.

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CORPORATE GOVERNANCE  •  BOARD COMPOSITION

Dr. Sohn was appointed as a director of the Company in 2010 and as a director of Western Alliance Bank since March 2017. He served as a director of Torrey Pines Bank from December 2010 until it merged into Western Alliance Bank in December 2013. Dr. Sohn is Smith Professor of Economics and Finance at California State University CI and a Commissioner on the Los Angeles City Employees Retirement System (LACERS) Board of Administration. He also currently serves on the boards of the National Association of Corporate Directors Southern California. Dr. Sohn was the Vice Chairman of multi-national retailer Forever 21 and was the President and Chief Executive Officer of Hanmi Financial Corporation, a commercial bank in Los Angeles, California. Before joining Hanmi in 2005, Dr. Sohn was an Executive Vice President and Chief Economic Officer of Wells Fargo Bank. Prior to his tenure at Wells Fargo, Dr. Sohn was a senior economist on the President’s Council of Economic Advisors in the White House, and has also been a tenured college professor in the Pennsylvania State University System. He is author of two books Global Financial Crisis and Exit Strategy and The New Economy . He has served on the boards of Port of Los Angeles, First California Bank, Foreign Affairs Council of Los Angeles, Children’s Bureau of Los Angeles, Ministers Mutual Life Insurance Company, L.A. Music Center (Performing Arts), Park Nicollet Health Services, The Blake School, Minnesota Community College System, North Memorial Medical Center, Harvard Business School Association of Minnesota and the American Heart Association of Minnesota. Dr. Sohn was educated at the University of Pittsburgh and Harvard Business School. In addition to world class abilities in economic forecasting, Dr. Sohn offers our Board of Directors expertise and experience in banking, management and the Southern California market.

Mr. Vecchione has been a director of the Company since October 2007 and served as the non-management Chairman of the Company’s bank subsidiary, Western Alliance Bank, from January 2014 to December 2015. Mr. Vecchione was reappointed as a director of Western Alliance Bank in March 2017. He served as Vice Chairman of Bank of Nevada from October 2010 to December 2013, and was the Company’s President and Chief Operating Officer from April 2010 to April 2013. In April 2013, Mr. Vecchione joined Encore Capital Group as President and a director, and became CEO of that company in June 2013. He also is Chairman of Cabot Credit Management, Encore Capital Group’s largest majority owned international subsidiary. During his more than 35-year career, Mr. Vecchione has held a number of senior positions at large financial services companies, including Chief Financial Officer at Apollo Global Management, LLC from 2007 to 2010 and Executive Vice President and Chief Financial Officer at AT&T Universal Card Services from 1997 to 1998. Between 1998 and 2006, Mr. Vecchione served in a number of positions at MBNA Corporation, including three years as Vice Chairman and Chief Financial Officer. Mr. Vecchione previously served as a director of International Securities Exchange from 2007 through June 2016. Mr. Vecchione served on the board of the Federal Home Loan Bank of San Francisco from 2012 through 2013. Mr. Vecchione also served as a director of Affinion Group and was the Chairman of its Audit Committee until January 2011. Mr. Vecchione provides valuable insight and guidance on the issues of corporate strategy and risk management, particularly as to his expertise and understanding of the current trends and regulatory issues within the financial services industry, and as to his diverse relationships within the financial services community.

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CORPORATE GOVERNANCE  •  DIRECTOR INDEPENDENCE

Director Independence

The Company’s common stock is traded on the NYSE. The NYSE’s rules require that a majority of directors of NYSE-listed companies be “independent.” For a director to be “independent” under the NYSE’s rules, the Board of Directors must affirmatively determine that the director has no material relationship with the Company, including its subsidiaries, either directly or as a partner, stockholder, or officer of an organization that has a relationship with the Company, and a director must satisfy all categorical standards relating to independence, as set forth in Section 303A of the NYSE Listed Company Manual.

Of the 14 persons nominated for election to the Board of Directors, 12 have been determined by the Board of Directors to be independent under NYSE standards. The Board of Directors based these determinations primarily on the recommendations of the Governance Committee, which performed a detailed review of the Company’s internal records and the responses of the directors to questions regarding employment and compensation history, affiliations and family and other relationships, and on discussions with such directors. As part of its review, the Governance Committee considered, among other things, the nature and extent of each director’s business relationships and transactions with the Company, its subsidiaries, and its executive officers and their affiliated business entities, including personal investment activities, professional services, and involvement in charitable or non-profit organizations.

Based on these factors, the Board of Directors determined that Mr. Sarver is not independent because he has served as executive officer of the Company and Western Alliance Bank within the last three years. Likewise, the Board of Directors determined that Mr. Hilton is not independent. In evaluating Mr. Hilton’s independence, the Board of Directors considered the fact that he is Chairman and CEO of Meritage Homes Corporation (“Meritage”), and Mr. Sarver is a member of the board of directors of Meritage. The board of directors of Meritage considers Mr. Sarver to be a non-independent director. In addition, the Board of Directors also considered the fact that Mr. Sarver is the Managing Partner of the entity which owns the Phoenix Suns NBA basketball team, and Mr. Hilton is a limited partner in the Phoenix Suns ownership group. Further, Mr. Hilton is an investor in multiple commercial real estate ventures in which Mr. Sarver also has a direct or indirect interest, and Mr. Sarver serves as trustee of certain trusts that Mr. Hilton has established for the benefit of his children. Accordingly, based on the totality of these circumstances, and notwithstanding that Mr. Hilton satisfies all of the NYSE’s categorical standards for independence, the Company’s Board of Directors concluded it is in the best interest of the Company’s stockholders that Mr. Hilton not be deemed an independent director.

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CORPORATE GOVERNANCE  •  MEETINGS OF THE BOARD OF DIRECTORS

Meetings of the Board of Directors

The Board of Directors held seven meetings in 2016. Each current director attended at least 75% of the meetings of the Board of Directors and meetings of committees on which he or she served in 2016. The Company invites and encourages all of its directors to attend the Company’s annual meetings of stockholders, and, with the exception of Mr. Patriarca, all of the directors attended the 2016 annual meeting of stockholders. Mr. Patriarca has attended all meetings of the Board of Directors and the committees on which he serves since his September 2016 appointment.

Executive sessions of non-management directors (consisting of all directors other than Mr. Sarver) and independent directors’ sessions (consisting of all directors other than Messrs. Sarver and Hilton) are regularly scheduled and held during the Company’s regular quarterly Board of Directors meetings.

Board Role in Risk Oversight

Under the Company’s governance structure and applicable law, the Board of Directors is ultimately responsible for overseeing the Company’s risk management processes. The Board of Directors discharges this duty in part through its duly appointed committees. A Directors Risk Committee (the “Risk Committee”) assists the Boards of Directors of the Company and its wholly-owned subsidiary, Western Alliance Bank, in fulfilling their oversight responsibilities with respect to the existence, operation and effectiveness of the enterprise risk management programs, policies and practices of the Company and its subsidiaries. The Risk Committee satisfies itself that sound policies, procedures and practices are implemented for the management of key risks under the Company’s Enterprise Risk Management framework, including credit, concentration, operational, market, regulatory, information technology, reputational, strategic, business, modelling, legal and external/environmental risks. The Risk Committee reports regularly to the Board of Directors regarding material matters discussed at meetings of the Risk Committee, as well as the current status of risk and action items. The Risk Committee assists the Board of Directors and its other committees with their risk-related activities, and acts as a resource to management, including the Company’s Enterprise Risk Management Committee (“ERMC”).

In addition, the other committees of the Board of Directors review and consider risks associated with their specific areas of responsibility. For example, in accordance with NYSE requirements, the Audit Committee reviews the Company’s internal controls and its major financial risk exposures and the steps management has taken to monitor and control such exposures. The Compensation Committee considers the risks associated with the Company’s compensation programs. For a discussion of the Compensation Committee’s review of the Company’s senior executive officer compensation plans and employee incentive compensation plans and the risks associated with those plans, see “ Evaluation of Company Compensation Plans and Risk ” on page 34 of this proxy statement. Likewise, the Finance and Investment Committee oversees the Company’s management of risks associated with its finance and investment functions. In accordance with the Dodd-Frank Wall Street Reform and Consumer Protection Act, the Company is required to conduct annual stress tests (“DFAST”). Effective January 24, 2017, the Board of Directors dissolved a special DFAST Committee it had created to oversee the DFAST process and assigned its specific DFAST Responsibilities to the Finance and Investment Committee and overall oversight of model risk management to the Risk Committee, including the responsibility for reviewing and approving inputs and assumptions, processes, methodologies, and outputs.

The Company has also dedicated substantial management resources to its internal risk management processes. The Company’s Chief Risk Officer (“CRO”) reports to both the Risk Committee and the Company’s Chief Operating Officer. The Company’s CRO oversees periodic comprehensive company-wide risk assessments and manages the Company’s enterprise risk management program. The CRO chairs the ERMC, which is composed of many of the Company’s senior executives and subject matter experts. Under its charter, the ERMC meets on a regular basis throughout the year and is responsible for: (1) identifying and prioritizing business and financial risks, consistent with our Risk Appetite Statement; (2) oversight of business process risk; (3) ensuring that any identified risk control gaps are addressed; and (4) continually improving the Company’s risk management infrastructure. The CRO provides regular reports on ERMC activities to the Risk Committee and the full Board of Directors.

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CORPORATE GOVERNANCE  •  NON-EMPLOYEE DIRECTOR STOCK OWNERSHIP GUIDELINES

Finally, because the Board of Directors believes that skilled and well-informed directors are vital to effectively fulfilling the governance responsibilities of the Board of Directors, including oversight of the Company’s risk management processes, it has adopted and implemented a formal Director Training and Education Program as part of its Corporate Governance Guidelines.

Non-Employee Director Stock Ownership Guidelines

The Board of Directors adopted Stock Ownership Guidelines for directors and executive officers because it believes that it is important for the Company’s future success that senior management and directors own and hold a minimum number of shares of common stock of the Company in order to further align their interests and actions with the interests of the Company’s stockholders. The Stock Ownership Guidelines require non-employee directors to own a minimum number of shares of the Company’s common stock, which is the lesser of 20,000 shares or the number of shares having a value at least equal to five times such director’s annual cash compensation as reported in the Company’s most recent proxy statement. The Stock Ownership Guidelines provide for a transition period of five years during which new directors must achieve full compliance with these requirements. The Stock Ownership Guidelines are administered and enforced by the Governance Committee of the Board of Directors, and compliance is monitored and reported to the Committee by the Company’s General Counsel. Each director is in full compliance with these requirements. Stock Ownership Guidelines for the Company’s executive officers can be found on page 33.

The Company understands that hedging and significant amounts of pledging of Company stock by directors and executive officers may skew the alignment of the interests between Company insiders and Company stockholders. Therefore, the Stock Ownership Guidelines specifically prohibit any hedging of Company stock held by directors and executive officers, exclude pledged shares from required ownership levels, and establish both individual and collective maximums on Company shares that may be placed in a margin account or otherwise pledged. A complete copy of the Stock Ownership Guidelines, and the restrictions on hedging and pledging contained therein, is included as an exhibit to the Corporate Governance Guidelines available in the Governance Documents section of the Investor Relations page of the Company’s website at www.westernalliancebancorporation.com or, for print copies, by writing to the Company at One E. Washington Street, Suite 1400, Phoenix, Arizona 85004, Attention: Corporate Secretary.

Communication with the Board of Directors and its Committees

Any stockholder or other interested person may communicate with the Board of Directors, a specified director (including the Lead Independent Director), the non-management directors as a group, or a committee of the Board of Directors by directing correspondence to their attention, in care of the Corporate Secretary, Western Alliance Bancorporation, One E. Washington Street, Suite 1400, Phoenix, Arizona 85004. Anyone who wishes to communicate with a specific director, the non-management directors only or a specific committee should send instructions asking that the material be forwarded to the appropriate director, group of directors or committee chairman. All communications so received from stockholders or other interested parties will be forwarded to the director or directors designated.

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CORPORATE GOVERNANCE  •  COMMITTEES OF THE BOARD OF DIRECTORS

Committees of the Board of Directors

The Company’s Board of Directors has FIVE standing committees:

Information with respect to each of these committees is set forth below.

The Company may appoint additional, or modify existing, committees of the Board of Directors in the future, including for purposes of complying with all applicable corporate governance rules of the NYSE. The structure and membership information for each of the Company’s five committees listed above are available in the Investors Relations section of the Company’s website at www.westernalliancebancorporation.com or, for print copies, by writing to the Company at One E. Washington Street, Suite 1400, Phoenix, Arizona 85004, Attention: Corporate Secretary. The charters for each of the Company’s five committees are available in the Investors Relations section of the Company’s website at www.westernalliancebancorporation.com .

Audit Committee

As of December 31, 2016, the Company’s Audit Committee consisted of five independent directors (Messrs. Beach, Sande, Latta, Patriarca, and Dr. Nagy). The Audit Committee held eleven meetings in 2016. Following committee reassignments on March 31, 2017, Dr. Sohn was appointed to the Audit Committee and Mr. Patriarca was appointed as Audit Committee Chairman. Mr. Sande and Dr. Nagy were not reappointed due to their not standing for election as directors in 2017.

The Board of Directors has determined that Mr. Beach meets the NYSE standard of possessing accounting or related financial management expertise. Each member of the Audit Committee is “financially literate” under NYSE listing standards, and the Board of Directors has determined that Mr. Beach qualifies as an “audit committee financial expert” as defined by the SEC. For information regarding the qualifications of each member of the Audit Committee, please see the biographical information set forth above. The Audit Committee’s primary duties and responsibilities are to:

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CORPORATE GOVERNANCE  •  COMMITTEES OF THE BOARD OF DIRECTORS

Compensation Committee

As of December 31, 2016, the Company’s Compensation Committee consisted of five independent directors (Ms. Johnson, Messrs. Boyd and Mack, and Drs. Sohn and Nave). Dr. Nave serves as the Compensation Committee’s Chairman. The Compensation Committee held six meetings in 2016. Following committee reassignments on March 31, 2017, Mr. Boyd and Dr. Sohn left the Compensation Committee and Messrs. Latta and Marshall were appointed. Each member of the Compensation Committee is also an outside director for purposes of Section 162(m) under the Internal Revenue Code of 1986, as amended (“Code”), and a non-employee director under the Section 16 of the Securities Exchange Act of 1934, as amended (“Exchange Act”).

The Compensation Committee’s powers, authority, responsibilities and duties include:

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CORPORATE GOVERNANCE  •  COMMITTEES OF THE BOARD OF DIRECTORS

The Compensation Committee also has the authority to delegate its authority to subcommittees and individual members of the Compensation Committee as the Compensation Committee deems appropriate; provided that any delegate shall report any actions taken to the whole Compensation Committee at its next regularly scheduled meeting. The “ Compensation Committee Report ” appears on page 35.

Nominating and Corporate Governance Committee

As of December 31, 2016, the Governance Committee consisted of five independent directors (Messrs. Boyd, Marshall, Gould, Vecchione, and Snyder). Mr. Snyder serves as Chairman of the Governance Committee. The Governance Committee held five meetings in 2016. Following committee reassignments on March 31, 2017, Mr. Marshall left the Governance Committee and Mr. Beach was appointed to the Governance Committee. The Committee’s primary duties include:

The Governance Committee also has the authority to delegate its authority to subcommittees and individual members of the Governance Committee as it deems appropriate; provided that any delegate shall report any actions taken to the whole Committee at its next regularly scheduled meeting. See “ Director Selection Process ” on page 5 for further information on the process by which directors are nominated for election to the Company’s Board of Directors.

Finance and Investment Committee

As of December 31, 2016, the Finance and Investment Committee (the “Finance Committee”) consisted of five independent directors (Messrs. Mack, Gould, Sande, and Drs. Nave and Sohn) and one non-independent director (Mr. Hilton). Dr. Sohn serves as Chairman of the Finance Committee. The Finance Committee held seven meetings in 2016. Following committee reassignments on March 31, 2017, Messrs. Gould and Sande left the Finance Committee and Mr. Vecchione was appointed to the Finance Committee. The Finance Committee is appointed by the Board of Directors to review strategies and oversee the effectiveness of financial management and investment activities at the Company and each of its subsidiaries. The Finance Committee’s duties include:

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CORPORATE GOVERNANCE • COMMITTEES OF THE BOARD OF DIRECTORS

Risk Committee

As of December 31, 2016, the Risk Committee consisted of five independent directors (Ms. Johnson, Messrs. Marshall, Latta, and Snyder, and Dr. Nagy). Mr. Marshall serves as Chairman of the Risk Committee. The Risk Committee held five meetings in 2016. Following committee reassignments on March 31, 2017, Mr. Latta and Dr. Nagy left the Risk Committee and Messrs. Gould and Patriarca were appointed to the Risk Committee. The Risk Committee is appointed by the Board of Directors to assist the Board of Directors of the Company and Western Alliance Bank in fulfilling its oversight responsibilities with respect to the existence, operation and effectiveness of the enterprise risk management programs, policies and practices of the Company and its subsidiaries’ risk management functions. The Risk Committee’s duties include:

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