Sec Form 4 Filing - OSGOOD STEVEN G @ National Storage Affiliates Trust - 2026-07-22

FORM 4 Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934, Section 17(a) of the Public Utility Holding Company Act of 1935 or Section 30(h) of the Investment Company Act of 1940

OMB APPROVAL OMB Number: 3235-0287 Expires: November 30, 2011 Estimated average burden hours per response... 0.5

1. Name and Address of Reporting Person OSGOOD STEVEN G 2. Issuer Name and Ticker or Trading Symbol National Storage Affiliates Trust [ NSA] 5. Relationship of Reporting Person(s) to Issuer (Check all applicable) X __ Director _____ 10% Owner _____ Officer (give title below) _____ Other (specify below) (Last) (First) (Middle) C/O NATIONAL STORAGE AFFILIATES TRUST, 8400 EAST PRENTICE AVENUE, 9TH FLOOR 3. Date of Earliest Transaction (MM/DD/YY) 07/22/2026 (Street) GREENWOOD VILLAGE, CO80111 4. If Amendment, Date Original Filed (MM/DD/YY) 6. Individual or Joint/Group Filing (Check Applicable Line) __ X __ Form filed by One Reporting Person _____ Form filed by More than One Reporting Person (City) (State) (Zip)

Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned 1.Title of Security (Instr. 3) 2. Transaction Date (MM/DD/YY) 2A. Deemed Execution Date, if any (MM/DD/YY) 3. Transaction Code (Instr. 8) 4. Securities Acquired (A) or Disposed of (D) (Instr. 3, 4 and 5) 5. Amount of Securities Beneficially Owned Following Reported Transaction(s) (Instr. 3 and 4) 6. Ownership Form: Direct (D) or Indirect (I) (Instr. 4) 7. Nature of Indirect Beneficial Ownership (Instr. 4) Code V Amount (A) or (D) Price Common shares of beneficial interest, $0.01 par value ( 1 ) 07/22/2026 D 5,232 D 0 ( 1 ) I See footnote ( 2 )

Table II - Derivative Securities Acquired, Disposed of, or Beneficially Owned ( e.g. , puts, calls, warrants, options, convertible securities) 1. Title of Derivative Security (Instr. 3) 2. Conversion or Exercise Price of Derivative Security 3. Transaction Date (MM/DD/YY) 3A. Deemed Execution Date, if any (MM/DD/YY) 4. Transaction Code (Instr. 8) 5. Number of Derivative Securities Acquired (A) or Disposed of (D) (Instr. 3, 4, and 5) 6. Date Exercisable and Expiration Date (MM/DD/YY) 7. Title and Amount of Underlying Securities (Instr. 3 and 4) 8. Price of Derivative Security (Instr. 5) 9. Number of Derivative Securities Beneficially Owned Following Reported Transaction(s) (Instr. 4) 10. Ownership Form of Derivative Security: Direct (D) or Indirect (I) (Instr. 4) 11. Nature of Indirect Beneficial Ownership (Instr. 4) Code V (A) (D) Date Exercisable Expiration Date Title Amount or Number of Shares Class A OP Units ( 3 ) ( 3 ) 07/22/2026 D 142,487 ( 3 ) ( 3 ) ( 4 ) Common shares of beneficial interest, $0.01 par value 142,487 ( 3 ) ( 3 ) 0 ( 3 ) I See footnote ( 2 )

Reporting Owners Reporting Owner Name / Address Relationships Director 10% Owner Officer Other OSGOOD STEVEN G C/O NATIONAL STORAGE AFFILIATES TRUST 8400 EAST PRENTICE AVENUE, 9TH FLOOR GREENWOOD VILLAGE, CO80111 X Signatures /s/ Steven G. Osgood, by Zoya F. Afridi, his Attorney-in-fact 07/22/2026 Signature of Reporting Person Date

Explanation of Responses:

( 1 )Pursuant to the Agreement and Plan of Merger, dated as of March 16, 2026 (the "Merger Agreement"), between the Issuer, Public Storage and certain other parties, common shares of beneficial interest, $0.01 par value of the Issuer, inclusive of restricted shares, were converted into the right to receive 0.1400 (the "Exchange Ratio") newly issued common shares of beneficial interest, par value $0.10 per share, of Public Storage and cash in lieu of any fractional shares. ( 2 )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. ( 3 )Pursuant to the Merger Agreement, each Class A OP Unit issued and outstanding immediately prior to the effective time of the Partnership Merger was (i) automatically converted into the right to receive a number of newly issued common units in Public Storage OP, L.P., equal to the Exchange Ratio or (ii), at the election of holders of Class A OP Units, redeemed in exchange for one newly issued unit in NSA OP JV, LLC which holds 80% of the equity of the joint venture with Public Storage that holds certain identified real estate assets contributed by the Partnership. ( 4 )N/A.

Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.

* If the form is filed by more than one reporting person, see Instruction 4(b)(v).

** Intentional misstatements or omissions of facts constitute Federal Criminal Violations. See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).

Note: File three copies of this Form, one of which must be manually signed. If space is insufficient, see Instruction 6 for procedure.
Persons who respond to the collection of information contained in this form are not required to respond unless the form displays a currently valid OMB Number.