COMPANHIA DE SANEAMENTO DE MINAS GERAIS - COPASA MG
Publicly Held Company Corporate Registry (NIRE) 313.000.363-75
CNPJ No. 17.281.106/0001-03
Companhia de Saneamento de Minas Gerais - COPASA MG (B3: CSMG3) ("COMPANY" or "COPASA MG"), in compliance with Brazilian Securities and Exchange Commission (CVM) Resolution No. 44, dated August 23, 2021, and further to the Material Facts disclosed on November 14, 2024, November 5, 2025,
December 17, 2025, January 28, 2026 and February 20, 2026, hereby informs its shareholders and the market in general that, on this date, it has received from its controlling shareholder, the State of Minas Gerais, the Official Letter SECGERAL/GAB GOVERNADOR No. 87/2026, informing of the publication, on April 23, 2026, of the "Manual for Participation in the Preliminary Phase of the Reference Investor Selection Process" ("Preliminary Phase Manual"), in preparation for a potential public secondary offering of common shares issued by the Company and held by the State of Minas Gerais.
The full version of the Preliminary Phase Manual and its annexes is available at: https://desenvolvimento.mg.gov.br/inicio/desestatizacaocopasa/oferta-publica (on this website, click on "Preliminary Phase Manual").
This Material Fact is for informational purposes only and does not constitute an investment recommendation, an offer to sell or a solicitation of an offer to buy any securities issued by the Company in Brazil, the United States of America or in any other jurisdiction.The Company will keep its shareholders and the market duly informed of any relevant developments regarding the matters described herein.
Belo Horizonte, April 23, 2026.
Adriano Rudek de Moura
Chief Financial and Investor Relations Officer