X0508 4 2025-06-24 0 0001585389 SmartStop Self Storage REIT, Inc. SMA 0001672825 Mueller David J 10 TERRACE ROAD LADERA RANCH CA 92694 1 0 0 0 0 Class A Common Stock 7190.87 D Long-Term Incentive Plan Units 0 2025-06-24 4 A 0 2814 0 A Class A Common Stock 2814 7234.25 D Long-Term Incentive Plan Units 0 Class A Common Stock 9598 9598 D Represents 7,190.87 shares of Class A Common Stock previously reported as being owned by the Reporting Person. Represents long-term incentive plan units ("LTIP Units") of SmartStop OP, L.P., the Issuer's operating partnership (the "Operating Partnership"). Vested LTIP Units are convertible into Class A common units of the Operating Partnership ("Class A Common Units"). Class A Common Units are redeemable by the holder for, at the election of the Issuer, shares of the Issuer's Class A Common Stock on a one-for-one basis or the cash value of such shares. The Reporting Person was awarded 2,814 LTIP Units upon his reelection to the board of directors, which LTIP Units vest one year from such reelection. Represents 9,598 LTIP Units previously reported as being owned by the Reporting Person, which LTIP Units vest ratably over four years commencing on the first anniversary of the issuance thereof, subject to the Reporting Person's continued employment or service through each vesting date. /s/ David J. Mueller 2025-06-26