SCHEDULE 13G 0001618360 XXXXXXXX LIVE Common Stock, par value $0.001 per share 03/31/2025 0001438133 TANDEM DIABETES CARE INC 875372203 12400 HIGH BLUFF DRIVE SAN DIEGO CA 92130 Rule 13d-1(c) Sessa Capital (Master), L.P. E9 0.00 4466307.00 0.00 4466307.00 4466307.00 N 6.71 PN Sessa Capital GP, LLC DE 4466307.00 0.00 4466307.00 0.00 4466307.00 N 6.71 OO Sessa Capital IM, L.P. DE 4466307.00 0.00 4466307.00 0.00 4466307.00 N 6.71 PN Sessa Capital IM GP, LLC DE 4466307.00 0.00 4466307.00 0.00 4466307.00 N 6.71 OO John Petry X1 4466307.00 0.00 4466307.00 0.00 4466307.00 N 6.71 IN TANDEM DIABETES CARE INC 12400 HIGH BLUFF DRIVE, SAN DIEGO, CA, 92130 (i) Sessa Capital (Master), L.P. (ii) Sessa Capital GP, LLC (iii) Sessa Capital IM, L.P. (iv) Sessa Capital IM GP, LLC (v) John Petry The address of the principal business office of each of the Reporting Persons is: 888 Seventh Avenue, 30th Floor, New York, NY 10019 (i) Sessa Capital (Master), L.P. - a Cayman Islands exempted limited partnership (ii) Sessa Capital GP, LLC - a Delaware limited liability company (iii) Sessa Capital IM, L.P. - a Delaware limited partnership (iv) Sessa Capital IM GP, LLC - a Delaware limited liability company (v) John Petry - a United States citizen Y (i) 4,466,307 (ii) 4,466,307 (iii) 4,466,307 (iv) 4,466,307 (v) 4,466,307 (i) 6.71% (ii) 6.71% (iii) 6.71% (iv) 6.71% (v) 6.71% (i) 0 (ii) 4,466,307 (iii) 4,466,307 (iv) 4,466,307 (v) 4,466,307 (i) 4,466,307 (i) 0 (ii) 4,466,307 (iii) 4,466,307 (iv) 4,466,307 (v) 4,466,307 (i) 4,466,307 Y N Not Applicable N Not Applicable N Not Applicable N Not Applicable N By signing below I certify that, to the best of my knowledge and belief, the securities referred to above were not acquired and are not held for the purpose of or with the effect of changing or influencing the control of the issuer of the securities and were not acquired and are not held in connection with or as a participant in any transaction having that purpose or effect, other than activities solely in connection with a nomination under ?? 240.14a-11. EXHIBIT INDEX TO SCHEDULE 13G EXHIBIT 1 Joint Filing Agreement, dated as of May 15, 2025, by and between Sessa Capital (Master), L.P., Sessa Capital GP, LLC, Sessa Capital IM, L.P., Sessa Capital IM GP, LLC, and John Petry. JOINT FILING AGREEMENT Pursuant to Rule 13D-1(k)(1) under the Securities Exchange Act of 1934, as amended, the undersigned agree, as of May 15, 2025, that only one statement containing the information required by Schedule 13G, and each amendment thereto, need to be filed with respect to the ownership by each of the undersigned of shares of Common Stock of Tandem Diabetes Care Inc and such statement to which this Joint Filing Agreement is attached as Exhibit 1 is filed on behalf of each of the undersigned. By: /s/ John Petry John Petry, individually, as manager of Sessa Capital GP, LLC, the general partner of Sessa Capital (Master), L.P, and as manager of Sessa Capital IM GP, LLC, the general partner of Sessa Capital IM, L.P. Date: May 15, 2025 Sessa Capital (Master), L.P. /s/ John Petry 05/15/2025 Sessa Capital GP, LLC /s/ John Petry 05/15/2025 Sessa Capital IM, L.P. /s/ John Petry 05/15/2025 Sessa Capital IM GP, LLC /s/ John Petry 05/15/2025 John Petry /s/ John Petry 05/15/2025