Additional Proxy Soliciting Materials (Form DEFA14A)

(Amendment No. )

Your Vote Counts! *The company will be hosting the meeting live via the Internet this year at the website address above. Please check the proxy materials for instructions on how to access the meeting. Smartphone users Point your camera here and vote without entering a control number For complete information and to vote, visit www.ProxyVote.com Control # T03550-P56755-Z93688 LAM RESEARCH CORPORATION 2026 Annual Meeting Vote by November 2, 2026 11:59 PM ET. For shares held in the 401(k) Plan, vote by October 29, 2026 11:59 PM ET. You invested in LAM RESEARCH CORPORATION and it's time to vote! You have the right to vote on proposals being presented at the Annual Meeting. This is an important notice regarding the availability of proxy materials for the stockholder meeting to be held on November 3, 2026. Get informed before you vote View the Notice and Proxy Statement and Annual Report online OR you can receive a free paper or email copy of the material(s) by requesting prior to October 20, 2026. If you would like to request a copy of the material(s) for this and/or future stockholder meetings, you may (1) visit www.ProxyVote.com, (2) call 1-800-579-1639 or (3) send an email to [email protected]. If sending an email, please include your control number (indicated below) in the subject line. There is no charge to you for requesting a copy. Unless requested, you will not otherwise receive a paper or email copy. Vote Virtually at the Meeting* November 3, 2026 9:30 a.m. Pacific Time Virtually at: www.virtualshareholdermeeting.com/LRCX2026 LAM RESEARCH CORPORATION ATTN: INVESTOR RELATIONS 4650 CUSHING PARKWAY FREMONT, CALIFORNIA 94538

Vote at www.ProxyVote.com THIS IS NOT A VOTABLE BALLOT This is an overview of the more complete proxy materials that are available to you on the Internet. You may view the proxy materials at www.ProxyVote.com or easily request a paper or email copy. We encourage you to access and review all of the important information contained in the proxy materials before voting. Please follow the instructions on the reverse side to vote these important matters. Prefer to receive an email instead? While voting on www.ProxyVote.com, be sure to click "Delivery Settings". 1. Election of Directors For Nominees: 1a. Timothy M. Archer 1b. Eric K. Brandt For 1c. Ita M. Brennan For 1d. Anirudh Devgan For 1e. John M. Dineen For 1f. Mark Fields For 1g. Ho Kyu Kang For 1h. Bethany J. Mayer For 1i. Jyoti K. Mehra For 1j. Abhijit Y. Talwalkar For 2. Advisory vote to approve our named executive officer compensation. For 3. Ratification of the appointment of KPMG LLP as our independent registered public accounting firm for fiscal year 2027. For 4. Stockholder proposal titled "Attainable Shareholder Right to Call for a Special Shareholder Meeting," if properly presented. Against NOTE: Such other business as may properly come before the annual meeting or any adjournment or postponement thereof. Voting Items Board Recommends T03551-P56755-Z93688