SONIDA SENIOR LIVING, INC.

Up to 18,710,689 Shares of Common Stock

This prospectus supplement supplements and amends the prospectus dated August 17, 2026 (the "Prospectus"), relating to the offer and resale, from time to time, by the selling securityholders named therein (the "Selling Stockholders") of up to 18,710,689 shares of the common stock, par value $0.01 per share (the "common stock"), of Sonida Senior Living, Inc. ("Sonida" or the "Company"), consisting of (a) 17,679,439 shares of common stock held by the Selling Stockholders and (b) up to 1,031,250 shares of common stock issuable upon the exercise, at an exercise price of $40.00 per share, of warrants held by certain of the Selling Stockholders.

This prospectus supplement is being filed solely to update the "Selling Stockholders" section of the Prospectus to reflect the distribution of shares of common stock previously issued to CPIF Sparti SAF, L.P. ("CPIF SAF") to certain of its limited partners. No additional securities are being registered by this prospectus supplement. The shares covered hereby were previously registered for resale pursuant to the registration statement referenced herein.

You should read this prospectus supplement, together with the related prospectus and the additional information described under the heading "Where You Can Find More Information; Incorporation of Certain Information by Reference," carefully before you invest in any of our securities.

Our common stock is listed on the New York Stock Exchange ("NYSE") and trades under the ticker symbol "SNDA." On August 21, 2026, the last reported sale price of our common stock on the NYSE was $39.56.

Investing in our securities involves risks. You should carefully consider the risk factors beginning on page 2 of the Prospectus and in Item 1A Risk Factors in the Company’s most recent Annual Report on Form 10-K and the other filings the Company makes with the Securities and Exchange Commission from time to time before you make an investment in our securities.