UNITED STATES
SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549
SCHEDULE 14A
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:

☐ 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 Rule 14a-12

MUELLER INDUSTRIES, INC.
(Name of Registrant as Specified In Its Charter)

(Name of Person(s) Filing Proxy Statement, if other than the Registrant)

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☒ No fee required.

☐ Fee paid previously with preliminary materials.

☐ Fee computed on table in exhibit required by Item 25(b) per Exchange Act Rules 14a-6(i)(1) and 0-11.

You invested in MUELLER INDUSTRIES, INC. and it's time to vote!

You have the right to vote on proposals being presented at the Special Meeting. This is an important notice regarding the availability of proxy material for the shareholder meeting to be held on September 26, 2023.

Get informed before you vote

View the Notice & Proxy Statement online OR you can receive a free paper or email copy of the material(s) by requesting prior to September 12, 2023. If you would like to request a copy of the material(s) for this and/or future shareholder meetings, you may (1) visit www.ProxyVote.com, (2) call 1-800-579-1639 or (3) send an email to sendmaterial@proxyvote.com. If sending an email, please include your control number (indicated below) in the subject line. Unless requested, you will not otherwise receive a paper or email copy.

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*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 at www.ProxyVote.com

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THIS IS NOT A VOTABLE BALLOT

This is an overview of the proposals being presented at the upcoming shareholder meeting. Please follow the instructions on the reverse side to vote these important matters.

Voting Items		Board Recommends
1.	Approve the amendment to the Company's Restated Certificate of Incorporation to increase the number of authorized shares of common stock by 150,000,000 shares.	FOR

THE PROXY, WHEN PROPERLY EXECUTED, WILL BE VOTED IN THE MANNER DIRECTED HEREIN BY THE SIGNED STOCKHOLDER. IF NO DIRECTION IS GIVEN, THE PROXY WILL BE VOTED II FOR II PROPOSAL 1.