ACM Research, Inc.

2026 Proxy Summary

This summary highlights information contained elsewhere in this Proxy Statement. This summary does not contain all of the information that you should consider, and you should read the entire Proxy Statement carefully before voting. References in this Proxy Statement to “ACM,” “ACM Research” and to “we,” “us,” “our” and similar terms refer to ACM Research, Inc.

Annual Meeting of Stockholders

Voting

Stockholders will be entitled to one vote for each outstanding share of Class A common stock they hold of record as of the record date and twenty votes for each outstanding share of Class B common stock they hold of record as of the record date.

Total Votes Per Proposal

161,059,224 votes, based on 61,223,064 shares of Class A common stock and 4,991,808 shares of Class B common stock outstanding as of the record date.

Annual Meeting Agenda

How to Cast Your Vote

You can vote by any of the following methods until 11:59 p.m., Eastern time, on June 9, 2026 or at the Annual Meeting on June 10, 2026:

Proposals

As our first proposal, we are asking stockholders to elect the following four director nominees, each of whom currently serves as a member of the board of directors. The following presents information as of April 13, 2026 with respect to each director nominee:

Director Nominee Representation

Diversity

Three of our director nominees voluntarily self-identify as having a diverse identity (gender or race).

Independence

Three of our four director nominees qualify as independent under SEC regulations and NASDAQ standards.

Tenure

The tenure of our director nominees reflects a mix of experience and perspective.

Board Diversity Matrix

Board Governance Practices

We are asking stockholders to ratify the audit committee’s retention of Ernst & Young Hua Ming LLP as our independent registered public accounting firm to examine and report on our consolidated financial statements and internal controls over financial reporting for the fiscal year ending December 31, 2026.

Participation in the Virtual Annual Meeting

The board of directors considers the appropriate format of our Annual Meeting of Stockholders on an annual basis. This year the board again chose a virtual meeting format for the Annual Meeting in an effort to facilitate stockholder attendance and participation by enabling stockholders to participate fully, and equally, from any location around the world, at no cost. The virtual meeting format will allow our stockholders to engage with us at the Annual Meeting from any geographic location, using any convenient internet connected devices, including smart phones and tablets, laptop or desktop computers. We will be able to engage with all stockholders as opposed to just those who can afford to travel to an in-person meeting. The virtual format allows stockholders to submit questions and comments during the meeting.

The live audio webcast of the Annual Meeting will be available for listening by the general public, but participation in the Annual Meeting, including voting shares and submitting questions, will be limited to stockholders. To ensure they can participate, stockholders and proxy holders should visit virtualshareholdermeeting.com/ACMR2026 and enter the 16-digit control number included on their Notice of Internet Availability of Proxy Materials or proxy card. If you wish to participate in the meeting and your shares are held in street name, you must obtain, from the broker, bank or other organization that holds your shares, the information required, including a 16-digit control number, in order for you to be able to participate in, and vote at, the Annual Meeting.

Stockholders can vote their shares and submit questions via the Internet during the Annual Meeting by accessing the Annual Meeting website at virtualshareholdermeeting.com/ACMR2026. We will answer any timely submitted questions on a matter to be voted on at the Annual Meeting before voting is closed on the matter. Following adjournment of the formal business of the Annual Meeting, we will address appropriate general questions from stockholders regarding ACM Research in the order in which the questions are received. Questions relating to stockholder proposals or ACM Research may be submitted in the field provided in the web portal at or before the time the questions are to be discussed. All questions received during the Annual Meeting will be presented as submitted, uncensored and unedited, except that we may omit certain personal details for data protection issues and we may edit profanity or other inappropriate language. If we receive substantially similar questions, we will group those questions together and provide a single response to avoid repetition. Additional information regarding the submission of questions during the Annual Meeting can be found in our 2026 Rules of Conduct and Procedure, a copy of which is attached hereto as Appendix A. Any material changes or updates to the 2026 Rules of Conduct and Procedure will be posted on our website and disclosed in a periodic report to the SEC on Form 8-K.

Online check-in to the Annual Meeting webcast will begin at 6:45 a.m., Pacific time, and you should allow ample time to log in to the meeting webcast and test your computer audio system. During online check-in and continuing through the length of the Annual Meeting, we will have technicians standing by to assist you with any technical difficulties you may have accessing the virtual meeting. If you encounter any difficulties accessing the Annual Meeting during the check-in or at meeting time, you should call the technical support number available at virtualshareholdermeeting.com/ACMR2026.

We have designed our virtual format to enhance, rather than constrain, stockholder access, participation and communication. For example, stockholders will be able to communicate with us during the Annual Meeting so they can ask questions. An audio replay of the Annual Meeting will be made publicly available at ir.acmrcsh.com/presentations until our 2027 annual meeting of stockholders.

This audio replay will include each stockholder question addressed during the Annual Meeting. We are utilizing technology from Broadridge Financial Solutions, Inc., or Broadridge, for the virtual meeting. The Broadridge platform is expected to accommodate most, if not all, stockholders.