Statement of Changes in Beneficial Ownership (Form 4)

FORM 4 Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b). Check this box to indicate that a transaction was made pursuant to a contract, instruction or written plan that is intended to satisfy the affirmative defense conditions of Rule 10b5-1(c). See Instruction 10.

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

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(Print or Type Responses)

1. Name and Address of Reporting Person * Japur Rafael Dorneles 2. Issuer Name and Ticker or Trading Symbol GERDAU S.A. [GGB] 5. Relationship of Reporting Person(s) to Issuer (Check all applicable) _____ Director _____ 10% Owner _____ Officer (give title below) __X__ Other (specify below) VP, CFO and IR Officer (Last) (First) (Middle) AVENUE DOUTORA RUTH DE CARDOSO, 8501, 8TH FLOOR, PINHEIROS 3. Date of Earliest Transaction (Month/Day/Year) 05/22/2026 (Street) SAO PAULO 05425-070 4. If Amendment, Date Original Filed (Month/Day/Year) 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 (Month/Day/Year) 2A. Deemed Execution Date, if any (Month/Day/Year) 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 Preferred shares 05/22/2026 S 5,000 D $4.75(1) 96,967 D

Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.
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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 (Month/Day/Year)

3A. Deemed Execution Date, if any (Month/Day/Year)

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 (Month/Day/Year)

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

Restricted Stock Units

$3.89(1)

02/12/2027

02/12/2027

Preferred shares

8,923

8,923

D

Restricted Stock Units

$3.89(1)

02/22/2027

02/22/2027

Preferred shares

46,634

46,634

D

Restricted Stock Units

$3.80(1)

08/01/2027

08/01/2027

Preferred shares

38,047

38,047

D

Restricted Stock Units

$3.65(1)

02/12/2028

02/12/2028

Preferred shares

15,830

15,830

D

Restricted Stock Units

$4.15(1)

02/12/2029

02/12/2029

Preferred shares

29,933

29,933

D

Restricted Stock Units

$4.15(1)

02/25/2029

02/25/2029

Preferred shares

81,108

81,108

D

Reporting Owners

Reporting Owner Name / Address	Relationships
	Director	10% Owner	Officer	Other
Japur Rafael Dorneles AVENUE DOUTORA RUTH DE CARDOSO, 8501 8TH FLOOR, PINHEIROS SAO PAULO 05425-070				VP, CFO and IR Officer

Signatures

/s/ Rafael Dorneles Japur		05/26/2026
**Signature of Reporting Person		Date

Explanation of Responses:

*	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).
(1)	The price is denominated in Brazilian reais and has been translated into U.S. dollars at the May 22 2026 selling rate of R$5.0140per US$1.00, as reported by the Central Bank of Brazil.

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