X0202 SCHEDULE 13D/A 0001193805-23-001215 0001105087 XXXXXXXX LIVE 9 Common Stock, par value $0.01 per share 05/28/2026 true 0000827187 83125X103 Sleep Number Corp

1001 THIRD AVENUE SOUTH MINNEAPOLIS MN 55404

STADIUM CAPITAL MANAGEMENT 203-972-8235 199 Elm Street 1325 Avenue of the Americas New Canaan CT 06840-5321 RYAN NEBEL 212-451-2300 OLSHAN FROME WOLOSKY LLP 1325 Avenue of the Americas New York NY 10019 0001105087 N STADIUM CAPITAL MANAGEMENT LLC AF N DE 0.00 953478.00 0.00 953478.00 953478.00 N 4.1 IA OO 0001580925 N Stadium Capital Management GP, L.P. AF N DE 0.00 953478.00 0.00 953478.00 953478.00 N 4.1 PN 0001987945 N Stadium Special Opportunity I, L.P. WC N DE 0.00 146297.00 0.00 146297.00 146297.00 N 0.6 PN 0001076204 N STADIUM CAPITAL PARTNERS L P WC N DE 0.00 807181.00 0.00 807181.00 807181.00 N 3.5 PN 0001473106 N SEAVER ALEXANDER M AF N X1 0.00 953478.00 0.00 953478.00 953478.00 N 4.1 IN Common Stock, par value $0.01 per share Sleep Number Corp 1001 THIRD AVENUE SOUTH MINNEAPOLIS MN 55404 Item 3 is hereby amended and restated to read as follows: The Shares beneficially owned by Stadium Capital were purchased using their investment capital or funds under management. The aggregate purchase price of 953,478 Shares beneficially owned by Stadium Capital was approximately $14,724,838 (including brokerage commissions and transaction costs). Item 5(a) is hereby amended and restated to read as follows: The responses of the Reporting Persons to rows 11 and 13 on the cover pages of this Amendment No. 9 to the Schedule 13D with respect to the aggregate number of Shares and percentage of the Shares beneficially owned by each of the Reporting Persons are incorporated herein by reference. As of the date hereof, the Reporting Persons collectively beneficially own 953,478 Shares, representing approximately 4.1% of the outstanding Shares. The percentages reported herein relating to beneficial ownership of Shares are based upon 23,049,000 Shares outstanding as of April 4, 2026, as reported in the Issuer's Quarterly Report on Form 10-Q filed with the Securities and Exchange Commission on May 12, 2026. The filing of this Schedule 13D shall not be deemed an admission that the Reporting Persons are, for purposes of Section 13(d) of the Exchange Act, the beneficial owners of any securities of the Issuer he or it does not directly own. Each of the Reporting Persons specifically disclaims beneficial ownership of the securities reported herein that he or it does not directly own. Item 5(c) is hereby amended and restated to read as follows: The transactions in the securities of the Issuer during the past 60 days by the Reporting Persons are set forth in Exhibit 1 and are incorporated herein by reference. All of such transactions were effected in the open market unless otherwise noted therein. As of the close of business on the date hereof, the Reporting Persons ceased to be the beneficial owners of more than 5% of the outstanding Shares. Item 7 is hereby amended to add the following exhibit: 1 - Transactions in Securities. STADIUM CAPITAL MANAGEMENT LLC /s/ Alexander M. Seaver 06/01/2026 Stadium Capital Management GP, L.P. /s/ Alexander M. Seaver 06/01/2026 Stadium Special Opportunity I, L.P. /s/ Alexander M. Seaver 06/01/2026 STADIUM CAPITAL PARTNERS L P /s/ Alexander M. Seaver 06/01/2026 SEAVER ALEXANDER M /s/ Alexander M. Seaver 06/01/2026