Information from ISFUT Instituto de Diagnóstico S.A. (INDISA) 2026

Dear particpants,

Depósito Central de Valores hereby provides information regarding the dividend payment that will be submitted for consideration and approval by the Ordinary Shareholders’ Meeting of Instituto de Diagnóstico S.A. (“Indisa” or “the company”), scheduled for Thursday, April 30, 2026 (the “Meeting”), and in accordance with what was reported at the 2022 Annual Shareholders’ Meeting and subsequent meetings, a procedure is made available to those shareholders who so desire, allowing them to opt to benefit from the Substitute Tax on Final Taxes paid by the company, with respect to the profits accumulated in Indisa’s Taxable Profits Fund (“ISFUT”), in accordance with the provisions of Transitory Article 25 of Law No. 21. 210 and the instructions issued by the Internal Revenue Service (the “SII”), in particular those contained in Circulars No. 43 of 2020 and No. 39 of 2021, and in Official Letters No. 215 and No. 2762 of 2021, and No. 762 of 2022. In this regard, we hereby inform you:

1) The ISFUT benefit allows Indisa to consider the payment of the complementary global tax as fulfilled for its individual shareholders who are residents of Chile (either directly or through other companies) and the payment of the additional tax in the case of shareholders not resident in Chile, allowing Indisa to distribute such profits with priority over others and without being subject to the general allocation rules set forth in Article 14 of the Income Tax Law.

2) In 2022, the amount of $38,765,726,436 was made available for application of the ISFUT benefit. In subsequent years, shareholders who have opted for it have applied it to their dividends, leaving a nominal balance as of today of $28,394,802. 570, which allows us to continue offering them, in this and in future dividend distributions of any kind, the option to apply their dividends to the ISFUT benefit until the amount is exhausted.

3) In accordance with the aforementioned SII instructions, taxpayers may choose to avail themselves of the ISFUT benefit at a rate of 30% on a portion or the entirety of the balance of accumulated taxable profits generated through December 31, 2016, with a deduction as a credit against the corresponding first-category tax already paid.

4) In light of the foregoing, and regarding the payment of the dividend agreed to be distributed at the Meeting, shareholders may instruct the company to withhold from their respective dividends the corresponding ISFUT payment for all or part of their shares registered in the shareholder registry at midnight on the fifth business day prior to the payment date; such withholding, after deducting credits for first-category tax already paid, shall amount to 12.15% of the respective dividend. For these purposes, shareholders who communicate their decision to receive dividends with ISFUT paid shall authorize the amount of the withholding from the dividend corresponding to their shares to be allocated to the proportional reimbursement of the amount paid by the company for ISFUT. In this manner, such shareholders shall bear the cost of paying said tax for the amount corresponding to them.

5) On the other hand, shareholders who decide not to bear the cost of the ISFUT paid by the company will receive the dividend agreed upon at the Meeting in full, for the entire amount, without any deduction whatsoever, and will be subject to the general tax rules applicable to that type of income. The same shall apply to shareholders who have not communicated, within the established time limit and/or in the established manner, their decision to avail themselves of the ISFUT benefit.

6) It should be noted that, if the Board’s dividend proposal is approved at the Meeting, the actual amount payable per share would be $42.30 for shareholders who do not avail themselves of the ISFUT benefit, and $37.20 for those who do. In either case, dividends will be paid to all shareholders within the usual timeframes and in accordance with standard dividend payment procedures.

7) Please note that shareholders entitled to receive the dividend who wish to exercise this option must complete and submit the “Instructions for the Substitute Tax on Final Taxes (ISFUT)” form to the email address [email protected], with a copy to [email protected], no later than May 15, 2026, at 1:00 p.m. The aforementioned form will be published and made available to shareholders on the company’s website www.indisa.cl once the Meeting has taken place and, therefore, the final dividend resolution is confirmed.

8) Shareholders who hold their shares in custody with a brokerage firm or a custodian bank must request that these entities send the “Instructions for the Substitute Tax on Final Taxes (ISFUT)” form to [email protected], with a copy to [email protected].

THIS INFORMATION, TOGETHER WITH THE ABOVE-MENTIONED INSTRUCTIONS, HAS BEEN PUBLISHED ON THE INDISA WEBSITE (WWW.INDISA.CL).