‎Material Fact - Amendment to the Bylaws

Companhia de Saneamento de Minas Gerais

Publicly-Held Company

COMPANY REGISTRY (NIRE): 313.000.363-75 CORPORATE TAXPAYER'S ID (CNPJ/MF): 17.281.106/0001-03

Companhia de Saneamento de Minas Gerais - COPASA MG (B3: CSMG3) ("COMPANY" or "COPASA MG"),

in compliance with CVM Resolution 44/2021, and further to the Material Facts disclosed on November 14, 2024, November 05, 2025, December 17, 2025, and January 28, 2026, hereby informs its shareholders and the market in general of the following.

On this date, the Company's Board of Directors approved, among other matters, the proposal to be submitted to the general shareholders' meeting for (i) the amendment of COPASA MG's bylaws, in order, among other changes, to allow for the adjustments required for the Company's privatization process, as authorized pursuant to State Law 25,664 of 2025 ("Privatization"), and (ii) the creation of a special class preferred share, to be held exclusively by the State of Minas Gerais, pursuant to Article 17, paragraph 7, of the Brazilian Corporation Law ("Golden Share").

Proposals will also be submitted to the general shareholders' meeting for the conversion of one (1) common share held by the State of Minas Gerais into one (1) Golden Share, and for the consolidation of the bylaws.

The amendment of the bylaws and the creation of the Golden Share, as well as the other matters to be submitted to the general shareholders' meeting, will be subject to the settlement of the secondary public offering of shares to be carried out by the State of Minas Gerais as part of the Company's privatization process ("Privatization Offering").

Further information and details regarding the proposals to be submitted to the general shareholders' meeting, as well as information on the call notice and on the attendance at the meeting, including the Management Proposal and the Participation Manual, will be made available in due course on the CVM website (https://www.gov.br/cvm/pt-br) and on the Company's Investor Relations website (https://ri.copasa.com.br/).

We hereby clarify that, on this date, no public offering of securities is being conducted given that the actual execution of the Privatization Offering is subject to, among other factors, all required and applicable approvals (including those of corporate nature and approvals from creditors), macroeconomic and market conditions in Brazil, the signing of final agreements, and procedures inherent to conducting public offerings under current regulations.

Accordingly, this Material Fact is for information purposes only and shall not, under any circumstances, be construed as, nor does it constitute any type of investment recommendation, an offer to sell, or a solicitation of an offer to buy any securities issued by the Company.

The Company will keep the market informed of any developments related to the subject of this Material Fact.

Belo Horizonte, January 29, 2026.

Adriano Rudek de Moura

Chief Financial and Investor Relations Officer