BANNER CORP

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

WASHINGTON, DC 20549

SCHEDULE 14A

INFORMATION

Proxy Statement Pursuant to Section 14(a) of the

Securities Exchange Act of 1934

Filed by the registrant ☒ Filed by a party other than the registrant ☐

Check the appropriate box:

BANNER CORPORATION

(Name of registrant as specified in its charter)

N/A

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

Payment of filing fee (Check all boxes that apply):

Proxy Statement

Dear

Shareholder:

You are cordially invited to attend the annual meeting of shareholders of Banner Corporation, which will be held on Wednesday, May 22, 2024, at 10:00 a.m., Pacific Time. Our 2024 annual meeting of shareholders will be a virtual meeting conducted solely online via live webcast. There is no physical location for the annual meeting. The online meeting format will facilitate remote shareholder attendance and participation, including the ability to vote your shares electronically and submit questions during the meeting.

You can attend the meeting by visiting https://meetnow.global/MULJV4V. To participate in the annual meeting, registered shareholders will need the control number included on their proxy card and all other shareholders will need to follow the instructions that accompanied their proxy materials.

The Notice of Annual Meeting of Shareholders and Proxy Statement describe the formal business to be transacted at the meeting. Directors and officers of Banner Corporation, as well as a representative of Moss Adams LLP, our independent registered public accounting firm, will be available to respond to shareholder questions. We intend to answer questions pertinent to our business immediately following the formal meeting of shareholders.

It is important that your shares are represented at the meeting, whether or not you attend the meeting virtually and regardless of the number of shares you own. To make sure your shares are represented, we urge you to vote promptly. You may vote your shares via the Internet or a toll-free telephone number, or by completing and mailing your proxy card. If you attend the virtual meeting as a shareholder, you may vote your shares at that time even if you have previously submitted your proxy.

We hope you can attend the virtual meeting.

Sincerely,

Mark J. Grescovich

President and Chief Executive Officer

Notice of Annual Meeting

of Shareholders

Items of Business

We will also consider and act upon such other matters as may properly come before the meeting or any adjournments or postponements thereof. As of the date of this notice, we are not aware of any other business to come before the annual meeting.

Your Vote is Important

To ensure your shares are represented at the meeting, please vote via the Internet or telephone, or sign, date and mail your proxy card which is solicited on behalf of the Board of Directors. The proxy will not be used if you attend and vote at the virtual annual meeting. Regardless of the number of shares you own, your vote is very important. Please act today.

Our 2024 annual meeting of shareholders will be a virtual meeting conducted solely online via live webcast. There is no physical location for the annual meeting. The online meeting format will facilitate remote shareholder attendance and participation, including the ability to vote your shares electronically and submit questions during the meeting. To participate in the annual meeting, registered shareholders will need the control number included on their proxy card and all other shareholders will need to follow the instructions that accompanied their proxy materials. Beneficial owners of shares held in street name must register in advance with Computershare no later than 5:00 p.m., Eastern Time, on May 17, 2024. (Late submissions will be processed to the extent feasible, but registration cannot be guaranteed in time for participation in the meeting.) To request registration, forward the proxy-granting email from your broker or email an image of your legal proxy tolegalproxy@computershare.com, with a subject line of “Legal Proxy,” or mail your request to Computershare, Banner Corporation Legal Proxy, P.O. Box 43006, Providence, RI 02940-3006. Computershare will confirm your registration by email and provide you with a unique control number necessary to participate fully in the meeting.

BY ORDER OF THE BOARD OF DIRECTORS

SHERREY LUETJEN

Secretary, Banner Corporation

Walla Walla, Washington

IMPORTANT: Voting promptly will save us the expense of further requests for proxies in order to ensure a quorum. You may vote via the Internet or by telephone or by submitting your proxy card by mail.