X0609 4 2026-05-15 0 0001618563 National Storage Affiliates Trust NSA 0001306273 OSGOOD STEVEN G false C/O NATIONAL STORAGE AFFILIATES TRUST 8400 EAST PRENTICE AVENUE, 9TH FLOOR GREENWOOD VILLAGE CO 80111 1 0 0 0 0 Common shares of beneficial interest, $0.01 par value 2026-05-15 4 A 0 5232 42.53 A 5232 I See footnote LTIP Units 2026-05-16 4 C 0 11451 D Class A OP Units 11451 0 I See footnote Class A OP Units 2026-05-16 4 C 0 11451 A Common shares of beneficial interest, $0.01 par value 11451 142487 I See footnote Consists of 5,232 restricted common shares of beneficial interest, $0.01 par value of the Issuer ("Restricted Shares"). The Restricted Shares were granted to the Reporting Person under the Issuer's 2024 Equity Incentive Plan, and are scheduled to vest scheduled to vest the earlier of: (i) May 15, 2027, (ii) the calendar day immediately preceding the next annual meeting of shareholders or (iii) immediately prior to the Company Merger Effective Time (as such term is defined in that certain Agreement of Plan and Merger, dated as of March 16, 2026, by and among the Issuer, NSA OP, LP (the "Partnership"), Public Storage, Public Storage OP, L.P., Pelican Merger Sub I, LLC and Pelican Merger Sub II, LLC, as the same may be amended). The closing price of the Issuer's common shares of beneficial interest, $0.01 par value ("Shares") on May 14, 2026. The Reporting Person's total direct and indirect beneficial ownership following the reported transaction in this class of securities is 5,232 Shares. The 5,232 Shares does not include derivative securities of the Reporting Person that have been previously reported on the Reporting Person's Forms 3 and Forms 4. Held by Steven Osgood TTEE Steven G. Osgood Trust dated 09/09/2019 for which the Reporting Person has voting and/or investment power. This filing shall not be deemed to be an admission that the Reporting Person is the beneficial owner of any of the securities reported herein, and the Reporting Person disclaims beneficial ownership of such securities except to the extent of the Reporting Person's pecuniary interest therein Long-term incentive plan units ("LTIP Units") in the Partnership, after achieving parity with Class A common units of limited partner interest in the Partnership ("Class A OP Units"), are eligible to be converted into Class A OP Units on a one-for-one basis upon the satisfaction of conditions set forth in the Partnership's agreement of limited partnership. Upon conversion of such vested parity LTIP Units into Class A OP Units, the Reporting Person has the right to cause the Partnership to redeem all or a portion of the Reporting Person's Class A OP Units for cash in an amount equal to the market value of an equivalent number of Shares, or at the Issuer's option, Shares on a one-for-one basis, subject to certain adjustments. Consists of 11,451 LTIP Units held by the Reporting Person which were converted into 11,451 Class A OP Units as described in footnote 5 above. The Reporting Person previously reported the 11,451 LTIP Units that were converted into Class A OP Units as described in this Form 4 as Class A OP Units on an as-converted basis. Accordingly, rows 1 and 2 of Table II of this Form 4 are being filed on a voluntary basis solely to provide notice of the conversion of the Reporting Person's 11,451 LTIP Units into 11,451 Class A OP Units. N/A The Reporting Person's total direct beneficial ownership following the reported transactions above is 142,487 Class A OP Units (which includes those Class A OP Units previously reported and the Class A OP Units reported herein) and 0 LTIP Units. The 142,487 Class A OP Units do not include non-derivative securities of the Reporting Person that were previously reported. Steven G. Osgood, by Zoya F. Afridi, his Attorney-in-fact 2026-05-19