UNITED STATES BANKRUPTCY COURT, NORTHERN DISTRICT OF CALIFORNIA, SANTA ROSA DIVISION In re Case No. 24-10545 CN (Lead Case) LEFEVER MATTSON, a California corporation, et al. (Jointly Administered) Debtors.1 Chapter 11 In re KS MATTSON PARTNERS, LP, NOTICE OF BAR DATE AND PROCEDURES FOR SUBMITTING Debtor. PROOFS OF CLAIM TO: ALL CREDITORS THAT HELD A CLAIM AGAINST KSMP AS OF THE NOVEMBER 22, 2024, PETITION DATE: THE GENERAL BAR DATE FOR CLAIMS IS OCTOBER 3, 2025 AT 11:59 P.M. (PREVAILING PACIFIC TIME) PLEASE TAKE NOTICE OF THE FOLLOWING: On August 28, 2025, the Bankruptcy Court entered an order setting deadlines (called “Bar Dates”) for filing claims in the chapter 11 case of KS Mattson Partners, LP (defined herein as “Debtor KSMP” or “KSMP”). The questions and answers below explain what the Bar Dates mean, who must file a claim, and how to do so. Want More Information or Need Help? Attend Our Town Hall! KSMP will host a town hall via Zoom on September 15, 2025 at 5:00 p.m. (Pacific Time) to discuss the process of completing and submitting proofs of claim. Information regarding the town hall can be found on the Claims Agent’s website at: https://veritaglobal.net/lm/info/14065. In the meantime, if you need help understanding the Proof of Claim, or the submission process, please contact KSMP’s counsel on KSMP@hoganlovells.com. 1. WHAT DOES THE TERM BAR DATE MEAN? The Bar Date is the date by which individuals and entities who assert a Claim against KSMP must submit a proof of claim with the Claims Agent in the manner indicated below. 2. WHAT IS A PROOF OF CLAIM? A Proof of Claim is the paperwork you submit to state the amount and nature of your claim in KSMP’s bankruptcy case. It consists of: • Form 410 (Official Proof of Claim Form), which must be completed and signed, and • Supporting documents that show the basis for your claim. For some creditors, a Proof of Claim may also include the Voluntary Questionnaire, if you choose to complete it. Why it matters: Filing a Proof of Claim ensures your claim is recognized and considered in the bankruptcy case. If you do not file your claim by the Bar Date, you may lose the right to pursue it. 3. WHO DOES THIS NOTICE APPLY TO AND WHEN IS THE DEADLINE? This Notice applies to anyone who may have a claim against KSMP. This Notice does not apply to those who only have claims against the LeFever Mattson Debtors or any other individual or entity affiliated with KSMP. • For creditors other than governmental entities: The Bar Date is October 3, 2025 at 11:59 p.m. Pacific Time. This includes: ° Claims that arose before November 22, 2024 (the petition date); and ° Claims that arose in the ordinary course of business between November 22, 2024 and June 9, 2025. • For governmental creditors (such as tax authorities): The Bar Date is December 8, 2025 at 11:59 p.m. Pacific Time. This Notice does not apply to claims that arose after June 9, 2025. Those claims will be addressed separately later. 4. DO YOU NEED TO SUBMIT A PROOF OF CLAIM? You must file a Proof of Claim if: ° Your claim is not listed in KSMP’s schedules of assets and liabilities (available on the Claims Agent’s website at Docket No. 1980); or ° Your claim is listed in those schedules, but it is marked as contingent, unliquidated, or disputed. If you are unsure whether you need to file, it is safest to file a proof of claim by the deadline. 5. WHAT ARE THE CONSEQUENCES OF NOT TIMELY AND PROPERLY SUBMITTING A PROOF OF CLAIM? IF A CREDITOR WHO IS REQUIRED TO SUBMIT A PROOF OF CLAIM DOES NOT DO SO IN A TIMELY MANNER OR IN THE PROPER FORM, SUCH CREDITOR SHALL BE FOREVER BARRED, ESTOPPED, AND ENJOINED TO THE FULLEST EXTENT ALLOWED BY APPLICABLE LAW FROM VOTING ON A PLAN OF REORGANIZATION, ASSERTING SUCH CLAIM IN KSMP’S CHAPTER 11 BANKRUPTCY AND RECEIVING A DISTRIBUTION UNDER A CONFIRMED PLAN FROM THE KSMP CHAPTER 11 ESTATE. 6. WHAT FORMS DO I NEED TO COMPLETE AND RETURN? 1) Proof of Claim Form (Official Form 410): This 3-page form is mandatory. All creditors must complete and return it by the deadline. 2) Voluntary Questionnaire: Certain creditors, called “Specialized Creditors” (explained below), are also asked to complete this form. It is not required, but it will help KSMP recreate its books and records and better understand the flow of funds between KSMP, the LeFever Mattson Debtors, and other third parties. KSMP believes that information gained through the Voluntary Questionnaire may expedite the resolution of this bankruptcy case—and, ultimately, distributions to creditors. If you do not complete the Voluntary Questionnaire, your proof of claim will still be valid so long as your Proof of Claim Form (Official Form 410) is properly completed and filed on time. 7. WHO ARE “SPECIALIZED CREDITORS” AND DO I NEED TO COMPLETE THE VOLUNTARY QUESTIONNAIRE? “Specialized Creditors” include: 1) Anyone who thinks they invested in a property with KSMP—even if their name isn’t on the title—and believes they may have a claim related to that investment; 2) Anyone who invested in Perris Freeway Plaza, LP, Specialty Properties Partners, LP, and Treehouse Investments, LP (three entities managed by KSMP that are not in bankruptcy but are believed to have once owned real estate); and 3) Anyone who thinks they have a claim because KSMP sold them an investment in a property or entity. As noted above, if you are a Specialized Creditor, you are asked (but not required) to complete the Voluntary Questionnaire in addition to your Proof of Claim Form. If you are not a Specialized Creditor, you only need to complete the Proof of Claim Form. 8. WHERE CAN I GET A COPY OF THE PROOF OF CLAIM FORM AND VOLUNTARY QUESTIONNAIRE? The forms are enclosed with this mailing. You can also get extra copies in the following ways: • Download for free from the Claims Agent’s website: https://veritaglobal.net/LM • Request by email: KSMP@hoganlovells.com • Call KSMP’s Claims Agent: (877) 709-4751 (U.S./Canada) or +1 (424) 236-7231 (International) • Download from the Bankruptcy Court’s website (www.canb.uscourts.gov) – note: this requires a PACER account and a small fee. 9. HOW DO I SUBMIT MY PROOF OF CLAIM FORM? You must complete and sign the enclosed Proof of Claim Form, attach any supporting documents, and make sure the Claims Agent actually receives it by October 3, 2025. You can submit your claim in one of two ways: 1. Online: Upload your form through Verita’s website at: https://veritaglobal.net 2. By mail, courier or hand delivery: KS Mattson Partners, LP Claims Processing Center, c/o KCC dba Verita, 222 N. Pacific Coast Highway, Suite 300, El Segundo, CA 90245 Important notes: • Do not send by fax or email—these will not be accepted. • If you file a paper claim, you must submit an original signed copy. • If you mail your proof of claim and want a stamped copy returned to you as proof of receipt, include a second copy (i.e., photocopy) of your submission plus a self-addressed, stamped envelope. • If mailing, do not send original supporting documents—send copies only. The Claims Agent will scan and may destroy attachments. • Specialized Creditors: Your claim may be treated as confidential if submitted through the Claims Agent. If you file directly on the public court docket instead, it will not be confidential. • DO NOT SEND IT TO KSMP, ITS LAWYERS, OR ITS PROFESSIONALS. 10. REQUESTS FOR ADDITIONAL INFORMATION AND COOPERATION. If after receiving a Proof of Claim, KSMP determines that additional information is needed to process your Claim, KSMP may contact you by telephone, mail, or email to request such additional information. 1 The last four digits of LeFever Mattson’s tax identification number are 7537. The last four digits of the tax identification number for KS Mattson Partners, LP (“KSMP”) are 5060. KSMP’s address for service is c/o Stapleton Group, 514 Via de la Valle, Solana Beach, CA 92075. The address for service on LeFever Mattson and all other Debtors is 6359 Auburn Blvd., Suite B, Citrus Heights, CA 95621. Due to the large number of debtor entities in these Chapter 11 Cases, a complete list of the Debtors and the last four digits of their federal tax identification numbers is not provided herein. A complete list of such information may be obtained on the website of the Debtors’ claims and noticing agent at https://veritaglobal.net/LM.