Fifth Supplemental Indenture dated as of December 18, 2023 between Citigroup Inc. and The Bank of New York Mellon, as trustee, to Indenture dated as of November 13, 2013

Exhibit 4.01

citigroup inc.

and

THE BANK OF NEW YORK MELLON

Trustee

FIFTH SUPPLEMENTAL INDENTURE

Dated as of December 18, 2023

Supplemental to Indenture dated as of November 13, 2013

providing for the issuance of

Senior Debt Securities

FIFTH SUPPLEMENTAL INDENTURE dated as of December 18, 2023 (this “Fifth Supplemental Indenture”), between Citigroup Inc., a Delaware corporation (the “Company”), and The Bank of New York Mellon, a New York banking corporation, not in its individual capacity but solely as trustee (the “Trustee”) under the Indenture dated as of November 13, 2013 (as supplemented prior to the date hereof, the “Indenture”).

WHEREAS, pursuant to Section 15.01(a)(iii) of the Indenture, the Company and the Trustee may enter into a supplemental indenture to change or eliminate any of the provisions of the Indenture; provided that any such change or elimination shall become effective only when there is no Outstanding Security of any series created prior to the execution of such supplemental indenture which is entitled to the benefit of such provision and as to which such supplemental indenture would apply;

WHEREAS, this Fifth Supplemental Indenture shall apply only to Securities issued on or after the date hereof and shall not apply to any Security that is Outstanding, or that is part of a series (as defined in Section 6.10 of the Indenture) any Security of which is Outstanding, on the date hereof;

WHEREAS, all acts and requirements necessary to make this Fifth Supplemental Indenture a legal, valid and binding obligation of the Company have been done;

WHEREAS, the Company desires to enter into this Fifth Supplemental Indenture and hereby requests that the Trustee enter into the same;

NOW, THEREFORE, the Company and the Trustee agree as follows:

ARTICLE ONE

Modifications

Section 1.01. Section 5.03 of the Indenture is hereby amended by deleting the existing clause (c) in its entirety and replacing it with the following:

“(c) If the Paying Agent shall be other than the Trustee, the Company will cause such Paying Agent to execute and deliver to the Trustee an instrument in which such Paying Agent shall agree with the Trustee, subject to the provisions of this Section 5.03 and Section 12.09, that such Paying Agent shall:

(i) hold all sums held by such Paying Agent for the payment of the principal of or interest on the Securities of that series in trust for the benefit of the holders of such Securities; and

(ii) at any time during the continuance of any default by the Company or any other obligor upon the Securities of that series in the making of any payment of the principal of or interest on the Securities of that series when the same shall have become due and payable, upon the written request of the Trustee, pay to the Trustee all sums so held in trust by such Paying Agent.”

Section 1.02 Section 5.06 of the Indenture is hereby amended by deleting clause (b) in its entirety.

Section 1.03. Section 10.01 of the Indenture is hereby amended by deleting the existing clause (o) in its entirety and replacing it with the following:

“(o) The Trustee shall not be deemed to have knowledge or notice of any default or event of default unless written notice of any event which is in fact such a default is received by a Responsible Officer of the Trustee at the Corporate Trust Office of the Trustee, and, if such notice is provided by the Company, such notice references the Securities and this Indenture.”

ARTICLE TWO

Miscellaneous

Section 2.01. The Trustee accepts the trusts created by this Fifth Supplemental Indenture upon the terms and conditions set forth in the Indenture. The Trustee shall not be responsible or accountable in any manner whatsoever for or in respect of, and makes no representation with respect to, the validity or sufficiency of this Fifth Supplemental Indenture or the due execution hereof by the Company and shall not be responsible in any manner whatsoever for or in respect of the correctness of the recitals and statements contained herein, all of which recitals and statements are made solely by the Company.

Section 2.02. Capitalized terms used but not defined in this Fifth Supplemental Indenture shall have the meanings given to such terms in the Indenture.

Section 2.03. Except as hereby expressly modified, the Indenture is in all respects ratified and confirmed and all the terms, conditions and provisions thereof shall remain in full force and effect.

Section 2.04. This Fifth Supplemental Indenture may be executed in any number of counterparts, each of which shall be deemed to be an original for all purposes; but such counterparts shall together be deemed to constitute but one and the same instrument.

Section 2.05. This Fifth Supplemental Indenture shall apply only to Securities issued on or after the date hereof and shall not apply to any Security that is Outstanding, or that is part of a series (as defined in Section 6.10 of the Indenture) any Security of which is Outstanding, on the date hereof.

IN WITNESS WHEREOF, each of CITIGROUP INC. and THE BANK OF NEW YORK MELLON, as Trustee, has caused this Fifth Supplemental Indenture to be signed by one of its officers thereunto duly authorized as of December 18, 2023.

IN WITNESS WHEREOF, each of CITIGROUP INC. and THE BANK OF NEW YORK MELLON, as Trustee, has caused this Fifth Supplemental Indenture to be signed by one of its officers thereunto duly authorized as of December 18, 2023.