UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

SCHEDULE 14A INFORMATION

Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934

(Amendment No.     )

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☐   Preliminary Proxy Statement	☐   Confidential, for Use of the Commission Only          (as permitted by Rule 14a-6(e)(2))
☐   Definitive Proxy Statement
☒   Definitive Additional Materials
☐   Soliciting Material under §240.14a-12

AVISTA CORPORATION

(Name of registrant as specified in its charter)

(Name of person(s) filing proxy statement, if other than the registrant)

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*** Exercise Your Right to Vote *** Important Notice Regarding the Availability of Proxy Materials for the Shareholder Meeting to Be Held on May 09, 2019 AVISTA CORP. AVISTA CORP. P.O. BOX 3727 SPOKANE, WA 99220-3727 Meeting Information Meeting Type: Annual Meeting For holders as of: March 08, 2019 Date: May 09, 2019 Time: 8:15 AM PDT Location: Avista Main Office Building 1411 E. Mission Avenue Spokane, WA 99202 You are receiving this communication because you hold shares in the above named company. This is not a ballot. You cannot use this notice to vote these shares. This communication presents only an overview of the more complete proxy materials that are available to you on the Internet. You may view the proxy materials online at www.proxyvote.com or easily request a paper copy (see reverse side). We encourage you to access and review all of the important information contained in the proxy materials before voting. See the reverse side of this notice to obtain proxy materials and voting instructions. 0000411455_1 R1.0.1.18

Before You Vote How to Access the Proxy Materials Proxy Materials Available to VIEW or RECEIVE: 1. Notice & Proxy Statement 2. Annual Report How to View Online: Have the information that is printed in the box marked by the arrow ï§ (located on the following page) and visit: www.proxyvote.com. How to Request and Receive a PAPER or E-MAIL Copy: If you want to receive a paper or e-mail copy of these documents, you must request one. There is NO charge for requesting a copy. Please choose one of the following methods to make your request: 1) BY INTERNET: www.proxyvote.com 2) BY TELEPHONE: 1-800-579-1639 3) BY E-MAIL*: sendmaterial@proxyvote.com * If requesting materials by e-mail, please send a blank e-mail with the information that is printed in the box marked by the arrow (located on the following page) in the subject line. Requests, instructions ï§ and other inquiries sent to this e-mail address will NOT be forwarded to your investment advisor. Please make the request as instructed above on or before April 25, 2019 to facilitate timely delivery. How To Vote Please Choose One of the Following Voting Methods Vote In Person: Many shareholder meetings have attendance requirements including, but not limited to, the possession of an attendance ticket issued by the entity holding the meeting. Please check the meeting materials for any special requirements for meeting attendance. At the meeting, you will need to request a ballot to vote these shares. Vote By Internet: To vote now by Internet, go to www.proxyvote.com. Have the information that is printed in the box marked by the arrow ï§ available and follow the instructions. Vote By Mail: You can vote by mail by requesting a paper copy of the materials, which will include a proxy card. 0000411455_2 R1.0.1.18

Voting items The Board of Directors recommends you vote FOR the following: 1. Election of Directors Nominees 1A Kristianne Blake 1B Donald C. Burke 1C Rebecca A. Klein 1D Scott H. Maw 1E Scott L. Morris 1F Marc F. Racicot 1G Heidi B. Stanley 1H R. John Taylor 1I Dennis P. Vermillion 1J Janet D. Widmann The Board of Directors recommends you vote FOR proposals 2 and 3. 2. Ratification of the appointment of Deloitte & Touche LLP as the Company’s independent registered public accounting firm for 2019. 3. Advisory (non-binding) vote on executive compensation. NOTE: The proxies will have discretionary authority to transact such other business as may come before the meeting or any adjournment or postponement thereof. 0000411455_3 R1.0.1.18

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