Exhibit 5(a)

                           [Citigroup Inc. Letterhead]

                                  July 19, 2006

Citigroup Inc.
Citigroup Funding Inc.
Safety First Trust Series 2006-1
Safety First Trust Series 2006-2
Safety First Trust Series 2006-3
Safety First Trust Series 2006-4
Safety First Trust Series 2006-5
Safety First Trust Series 2006-6
Safety First Trust Series 2006-7
Safety First Trust Series 2006-8
Safety First Trust Series 2006-9
Safety First Trust Series 2006-10

c/o Citigroup Funding Inc.
399 Park Avenue
New York, NY 10043

          Re:  Citigroup Inc.
               Citigroup Funding Inc.
               Safety First Trust Series 2006-1
               Safety First Trust Series 2006-2
               Safety First Trust Series 2006-3
               Safety First Trust Series 2006-4
               Safety First Trust Series 2006-5
               Safety First Trust Series 2006-6
               Safety First Trust Series 2006-7
               Safety First Trust Series 2006-8
               Safety First Trust Series 2006-9
               Safety First Trust Series 2006-10
               Registration Statement on Form S-3

Ladies and Gentlemen:

          I am General Counsel, Finance and Capital Markets of Citigroup Inc., a
Delaware corporation (the "GUARANTOR"), and have acted as legal counsel to
Citigroup Funding Inc., a Delaware corporation (the "COMPANY"), in connection
with the preparation of an automatic shelf registration statement on Form S-3
(the "REGISTRATION STATEMENT") filed by the Guarantor, the Company, Safety First
Trust Series 2006-1, Safety First Trust Series 2006-2, Safety First Trust Series
2006-3, Safety First Trust Series 2006-4, Safety First Trust Series 2006-5,
Safety First Trust Series 2006-6, Safety First Trust Series 2006-7, Safety First
Trust Series 2006-8, Safety First Trust Series 2006-9 and Safety First Trust
Series 2006-10 (each, a "TRUST" and, collectively, the "TRUSTS"), each a
statutory trust formed under the laws of the State of Delaware, with the
Securities and Exchange Commission under the Securities Act of 1933, as amended,



including the applicable rules and regulations thereunder (the "SECURITIES
ACT"). The Registration Statement relates to the issuance and sale from time to
time, pursuant to Rule 415 under the Securities Act, of the following
securities: (i) Principal-Protected Trust Certificates (the "CERTIFICATES") of
each Trust; and (ii) a guarantee of the Company with respect to the Certificates
of each Trust and a guarantee of the Guarantor with respect to the Company's
guarantee obligations of the Certificates of each Trust.

          The Certificates of each Trust are to be issued pursuant to the
Amended and Restated Declaration of Trust (the "DECLARATION") of such Trust to
be entered into among the Company, as sponsor, the Guarantor, U.S. Bank Trust
National Association, as Delaware trustee, U.S. Bank National Association, as
institutional trustee (the "INSTITUTIONAL TRUSTEE"), and Scott Freidenrich,
Geoffrey S. Richards and Cliff Verron, as regular trustees.

          This opinion is being delivered in accordance with Item 601(b)(5) of
Regulation S-K under the Securities Act.

          In connection with this opinion, I, along with persons employed by the
Guarantor and its subsidiaries, including the Company, with whom I have
consulted, have examined and are familiar with originals, or copies certified or
otherwise identified to our satisfaction, of (i) the Registration Statement;
(ii) the form of prospectus relating to the Certificates included in the
Registration Statement (the "PROSPECTUS"); (iii) the form of Declaration
(including the designation of terms of the Certificates annexed thereto); (iv)
the form of Principal-Protected Trust Certificates Guarantee Agreement (the
"GUARANTEE AGREEMENT") to be entered into among the Company, the Guarantor and
U.S. Bank National Association, as guarantee trustee (the "GUARANTEE TRUSTEE");
(v) the Trust Certificates Underwriting Agreement Basic Provisions, to be
incorporated by reference into a terms agreement for the Certificates of each
Trust to be entered into among each Trust, the Company, the Guarantor and one or
more underwriters (such terms agreement, together with the Basic Provisions, the
"UNDERWRITING AGREEMENT"); (viii) the Certificate of Incorporation of the
Company; (ix) the By-Laws of the Company currently in effect; (x) the Restated
Certificate of Incorporation of the Guarantor, as amended to date; (xi) the
By-Laws of the Guarantor currently in effect; (xii) certain resolutions adopted
by the Board of Directors of the Company; and (xiii) certain resolutions adopted
by the Board of Directors of the Guarantor.

          I (or such persons) have also examined and am familiar with originals,
or copies certified or otherwise identified to my satisfaction, of such
corporate records of the Company and the Guarantor, certificates of public
officials and other documents, and have conducted such other investigations of
fact and law as I (or such persons) have deemed appropriate as a basis for the
opinions expressed below. In such examination, I (or such persons) have assumed
the legal capacity of all natural persons, the genuineness of all signatures,
the authenticity of all documents submitted to me (or such persons) as
originals, the conformity to original documents of all documents submitted to me
(or such persons) as certified or photostatic copies and the authenticity of the
originals of such copies.

          Based upon and subject to the foregoing, I am of the opinion that,
upon (i) delivery and filing of the Prospectus with respect to such Trust in
compliance with the Securities Act; (ii) due authorization, execution and
delivery of each of the Guarantee Agreement, the


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Declaration and the Underwriting Agreement with respect to such Trust by the
parties thereto; (iii) due qualification of the Institutional Trustee and the
Guarantee Trustee under the Trust Indenture Act of 1939, as amended; (iv)
establishment of the terms of such Certificates in accordance with the
Declaration of such Trust; (v) due execution, authentication and delivery of
such Certificates in accordance with the Declaration of such Trust; and (vi) the
issuance of such Certificates against payment therefore in the manner described
in the Underwriting Agreement for such Certificates, the Guarantee Agreement of
such Trust will be a legal, valid and binding agreement of the Company and the
Guarantor, enforceable against the Company and the Guarantor in accordance with
its terms.

          Insofar as my opinion relates to the validity, binding effect or
enforceability of any agreement or obligation of the Company or the Guarantor,
it is subject to applicable bankruptcy, insolvency, reorganization, fraudulent
conveyance, moratorium and other similar laws affecting creditors' rights
generally from time to time in effect and subject to general principles of
equity, regardless of whether such is considered in a proceeding in equity or at
law.

          This opinion is limited to matters governed by the federal laws of the
United States of America, the laws of the State of New York and the General
Corporation Law of the State of Delaware (including the applicable provisions of
the Delaware Constitution and the reported judicial decisions interpreting the
General Corporation Law of the State of Delaware and such applicable provisions
of the Delaware Constitution). I am not admitted to the practice of law in the
State of Delaware.

          I consent to the filing of this opinion in the Registration Statement.
In giving this consent, I do not thereby admit that I come within the category
of persons whose consent is required under Section 7 of the Securities Act.

                                        Very truly yours,


                                        /s/ Michael S. Zuckert
                                        ----------------------------------------
                                        Michael S. Zuckert


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