Alto Ingredients, Inc.

SCHEDULE 14A INFORMATION

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

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**ALTO INGREDIENTS, INC.

1300 South Second Street

Pekin, Illinois 61554

May 7, 2026

Dear Fellow Stockholder:

Alto Ingredients, Inc.’s financial results for 2025 reflect continued execution of our strategic initiatives designed to improve operational performance, diversify revenue streams, and enhance returns on assets.

Beginning in late 2024 and through the first quarter of 2025, we implemented actions to improve our operating model. These actions included aligning staffing levels with our current operating footprint, removing structural costs, exiting certain underperforming activities in our Marketing and Distribution segment, and continuing to evaluate opportunities to unlock long-term value through our optimization and monetization plan for our Western assets. At the same time, we invested in improving operational efficiency and throughput across our plants and maintained operational discipline in support of our diversification efforts.

As a result of these actions and favorable operating conditions, net income increased by $72 million to $12 million for 2025 compared to 2024, and adjusted EBITDA grew by $53 million to $45 million over the same periods.

Renewable fuel export sales were one example of our diversification strategy. Beginning in late 2024 and throughout 2025, our Pekin Campus facilities shipped qualified renewable fuel to international markets, including the European Union. These export sales contributed to our financial results for the year.

Another diversification initiative included our acquisition, at the beginning of 2025, of a beverage-grade liquid carbon dioxide processing facility located adjacent to our Columbia ethanol plant in Boardman, Oregon. We integrated the acquired operations and realized operational efficiencies, and the business contributed to improved results from our Western Production segment during 2025. Demand for liquid carbon dioxide remained strong in the Pacific Northwest due to supply constraints and industrial and food and beverage end-market demand. We expect to continue evaluating opportunities to expand throughput and storage capacity, subject to market conditions and capital availability.

During 2025, legislation extending the Section 45Z clean fuel production tax credit through the end of 2029 was enacted. Both our Columbia and Pekin Campus dry mill facilities qualified for a $0.10 per gallon gross tax credit for 2025, and we recorded $7.5 million of Section 45Z credit earnings for the year, net of estimated monetization costs. For 2026, based on current regulations and assumptions, we anticipate continued eligibility under the program; however, actual results may differ based on regulatory interpretation and market conditions. We continue to pursue opportunities to lower the carbon intensity of our operations.

Having completed key initiatives to address losses at underperforming assets, remove structural costs, and reposition our portfolio toward higher value revenue streams, Alto Ingredients entered 2026 from a position of greater operating strength. We remain focused on disciplined capital allocation, maintaining cost controls, and executing initiatives intended to improve profitability and asset performance. Planned capital projects currently total approximately $25 million, subject to Board approval and prioritization based on expected returns.

In conclusion, the progress we have made is remarkable and we are excited about the path forward.

Invitation to our Annual Meeting

We cordially invite you to attend the 2026 annual meeting of stockholders of Alto Ingredients which will be held at 9:00 a.m., local time, on Tuesday, June 23, 2026, at our headquarters at 1300 South Second Street, Pekin, Illinois 61554. All stockholders of record at the close of business on April 28, 2026 are entitled to vote at the annual meeting. The formal meeting notice and Proxy Statement are attached.

At this year’s annual meeting, we will ask stockholders to (1) elect five directors; (2) cast an advisory vote to approve our executive compensation; (3) approve our 2026 Omnibus Incentive Plan; and (4) ratify the appointment of RSM US LLP to serve as our independent registered public accounting firm for the year ending December 31, 2026.

In addition, stockholders will transact any other business that may properly come before the annual meeting. A report on the business operations of Alto Ingredients will also be presented at the meeting and stockholders will have an opportunity to ask questions.

We use the Internet as our primary means of furnishing proxy materials to our stockholders. Accordingly, most stockholders will not receive paper copies of our proxy materials. We will instead send each stockholder a notice with instructions for accessing the proxy materials and voting electronically over the Internet or by telephone. The notice also provides information on how stockholders may request paper copies of our proxy materials. We believe electronic delivery of our proxy materials and annual report will help us reduce the environmental impact and costs of printing and distributing paper copies and improve the speed and efficiency by which our stockholders can access these materials.

Whether or not you plan to attend the annual meeting, it is important that your shares are represented and voted at the meeting, and we urge you to vote as soon as possible. As an alternative to voting in person at the annual meeting, you may vote electronically over the Internet or by telephone, or if you receive a proxy card or voting instruction form in the mail, by mailing the completed proxy card or voting instruction form. Timely voting by any of these methods will ensure your representation at the annual meeting.

For admission to the annual meeting, each stockholder may be asked to present valid picture identification, such as a driver’s license or passport, and proof of ownership of our capital stock as of the record date, such as the enclosed proxy card or a brokerage statement reflecting stock ownership. As always, we encourage you to vote your shares prior to the annual meeting.

On behalf of everyone at Alto Ingredients, thank you for your continued support. We hope that you will be able to join us on June 23 rd.

Sincerely,

Bryon T. McGregor,

President and Chief Executive Officer

NOTICE OF THE 2026 ANNUAL MEETING OF STOCKHOLDERS

TO BE HELD JUNE 23, 2026

NOTICE IS HEREBY GIVEN that the 2026 annual meeting (“Annual Meeting”) of stockholders of Alto Ingredients, Inc., a Delaware corporation, will be held at 9:00 a.m., local time, on Tuesday, June 23, 2026, at our headquarters at 1300 South Second Street, Pekin, Illinois 61554, for the following purposes, as more fully described in the Proxy Statement accompanying this notice:

All stockholders of record at the close of business on April 28, 2026 are entitled to notice of and to vote at the Annual Meeting and any adjournment(s) or postponement(s) thereof.

We cordially invite all stockholders to attend the Annual Meeting in person. Whether or not you plan to attend, it is important that your shares are represented and voted at the meeting. As an alternative to voting in person at the Annual Meeting, you can vote your shares electronically over the Internet, or if you receive a proxy card or voting instruction form in the mail, by mailing the completed proxy card or voting instruction form. For detailed information regarding voting instructions, please refer to the section entitled “How do I vote?” on page 4 of the Proxy Statement.

For admission to the Annual Meeting, each stockholder may be asked to present valid picture identification, such as a driver’s license or passport, and proof of ownership of our capital stock as of the record date, such as the enclosed proxy card or a brokerage statement reflecting stock ownership.

By Order of the Board of Directors,

Gilbert E. Nathan,

Chairman of the Board

Pekin, Illinois

May 7, 2026

INTERNET AVAILABILITY OF PROXY MATERIALS

WE USE THE INTERNET AS OUR PRIMARY MEANS OF FURNISHING PROXY MATERIALS TO OUR STOCKHOLDERS. CONSEQUENTLY, MOST STOCKHOLDERS WILL NOT RECEIVE PAPER COPIES OF OUR PROXY MATERIALS, ALTHOUGH SOME STOCKHOLDERS MAY CONTINUE TO RECEIVE PAPER COPIES IN ACCORDANCE WITH THEIR EXISTING DELIVERY PREFERENCES OR APPLICABLE RULES. WE WILL INSTEAD SEND EACH STOCKHOLDER A NOTICE OF INTERNET AVAILABILITY OF PROXY MATERIALS WITH INSTRUCTIONS FOR ACCESSING OVER THE INTERNET THE PROXY MATERIALS, INCLUDING OUR PROXY STATEMENT AND ANNUAL REPORT, AND VOTING ELECTRONICALLY OVER THE INTERNET OR BY TELEPHONE. THE NOTICE OF INTERNET AVAILABILITY OF PROXY MATERIALS ALSO PROVIDES INFORMATION ON HOW STOCKHOLDERS MAY OBTAIN PAPER COPIES OF OUR PROXY MATERIALS IF THEY SO CHOOSE. WE BELIEVE ELECTRONIC DELIVERY OF OUR PROXY MATERIALS AND ANNUAL REPORT WILL HELP ALTO INGREDIENTS, INC. REDUCE THE ENVIRONMENTAL IMPACT AND COSTS OF PRINTING AND DISTRIBUTING PAPER COPIES AND IMPROVE THE SPEED AND EFFICIENCY BY WHICH YOU CAN ACCESS THESE MATERIALS. IF YOU PREVIOUSLY ELECTED TO RECEIVE OUR PROXY MATERIALS ELECTRONICALLY, THESE MATERIALS WILL CONTINUE TO BE SENT VIA EMAIL UNLESS YOU CHANGE YOUR ELECTION.

PROXY STATEMENT

FOR THE 2026 ANNUAL MEETING OF STOCKHOLDERS

JUNE 23, 2026

TABLE OF CONTENTS

APPENDICES

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1300 South Second Street

Pekin, Illinois 61554

PROXY STATEMENT

FOR THE 2026 ANNUAL MEETING OF STOCKHOLDERS