X0202 SCHEDULE 13G 0002052113 XXXXXXXX LIVE Series H Mandatory Redeemable Preferred Shares 08/31/2026 0001285650 Calamos Global Total Return Fund 128118*73 2020 Calamos Court Naperville IL 60563 Rule 13d-1(b) BlackRock Portfolio Management LLC b DE 0.00 360000.00 0.00 360000.00 360000.00 N 100 HC Calamos Global Total Return Fund 2020 Calamos Court, Naperville, IL 60563 This statement is filed on behalf of BlackRock Portfolio Management LLC (the "Reporting Person"). In accordance with SEC Release No. 34-39538 (January 12, 1998), this Schedule 13G reflects the securities beneficially owned, or deemed to be beneficially owned, by certain business units (collectively, the "Reporting Business Units") of BlackRock, Inc. and its subsidiaries and affiliates. It does not include securities, if any, beneficially owned by other business units whose beneficial ownership of securities are disaggregated from that of the Reporting Business Units in accordance with such release. The business address of the Reporting Person is 50 Hudson Yards, New York, NY 10001. The Reporting Person is organized under the laws of the State of Delaware. N HC The Reporting Person may be deemed to share beneficial ownership of 360,000 shares of the Issuer's Series H Mandatory Redeemable Preferred Shares. The percentage reflected herein is based on 360,000 Series H Mandatory Redeemable Preferred Shares outstanding. 100% 0 360,000 0 360,000 Y N Various persons have the right to receive or the power to direct the receipt of dividends from, or the proceeds from the sale of the shares of Calamos Global Total Return Fund. No one person's interest in the shares of Calamos Global Total Return Fund is more than five percent of the total outstanding shares, except for (i) The Guardian Life Insurance Company of America, (ii) The Guardian Insurance & Annuity Company, Inc., and (iii) Midland National Life Insurance Company. N See Exhibit 99.1 Y Y N By signing below I certify that, to the best of my knowledge and belief, the securities referred to above were acquired and are held in the ordinary course of business and were not acquired and are not held for the purpose of or with the effect of changing or influencing the control of the issuer of the securities and were not acquired and are not held in connection with or as a participant in any transaction having that purpose or effect, other than activities solely in connection with a nomination under § 240.14a-11. Exhibit 24.1: Power of Attorney Exhibit 99.1: Item 7 BlackRock Portfolio Management LLC /s/ Joseph Virgilio 09/08/2026