EXHIBIT (5) & (23)


April 4, 2006



Merrill Lynch & Co., Inc.
4 World Financial Center
New York, New York 10080

Ladies and Gentlemen:

As your counsel, we have examined a copy of the Restated Certificate of
Incorporation, as amended, of Merrill Lynch & Co., Inc. (the "Company"),
certified by the Secretary of State of the State of Delaware. We are familiar
with the corporate proceedings had in connection with the proposed issuance
and sale by the Company to Merrill Lynch, Pierce, Fenner & Smith Incorporated
("MLPF&S"), pursuant to a Distribution Agreement dated December 15, 2004 (the
"Distribution Agreement") between the Company and MLPF&S, of the Company's 8%
Callable STock Return Income DEbt Securities(SM) due April 4, 2007 payable on
the maturity date with Halliburton Company common stock (the "Securities") in
an amount equal to $28,000,000 aggregate original public offering price of the
Securities. We have also examined a copy of the Indenture between the Company
and JPMorgan Chase Bank, N.A. as Trustee, dated as of April 1, 1983, as
amended (the "Indenture"), and the Company's Registration Statement on Form
S-3 (File No. 333-122639) relating to the Securities (the "Registration
Statement").

Based upon the foregoing and upon such further investigation as we
deemed relevant in the premises, we are of the opinion that:

1. The Company has been duly incorporated under the laws of the State of
Delaware.

2. The Securities have been duly and validly authorized by the Company
and, when the Securities have been duly executed and authenticated in
accordance with the terms of the




Indenture and delivered against payment therefor as set forth in the
Distribution Agreement, the Securities will constitute valid and legally
binding obligations of the Company, enforceable against the Company in
accordance with their terms, except to the extent that enforcement thereof may
be limited by bankruptcy, moratorium, insolvency, reorganization or similar
laws relating to or affecting creditors' rights generally and except as
enforcement thereof is subject to general principles at equity (regardless of
whether enforcement is considered in a proceeding in equity or at law).

We consent to the filing of this opinion as an exhibit to the
Registration Statement and as an exhibit to the Current Report of the Company
on Form 8-K dated April 4, 2006. We also consent to the use of our name under
the caption "United States Federal Income Taxation" in the pricing supplement
related to the offering of the Securities.


Very truly yours,



/s/ SIDLEY AUSTIN LLP