EXHIBIT 5(b)



                                  June 3, 2005


CMS Energy Corporation
CMS Energy Trust IV
CMS Energy Trust V
One Energy Plaza
Jackson, Michigan 49201




                  Re:      CMS Energy Corporation
                           CMS Energy Trust IV
                           CMS Energy Trust V
                           Registration Statement on Form S-3

Dear Ladies and Gentlemen:

                  We have acted as special counsel to CMS Energy Trust IV and
CMS Energy Trust V (each a "CMS Trust" and, together, the "CMS Trusts"), each a
statutory business trust formed under the Business Trust Act of the State of
Delaware, in connection with the preparation of a Registration Statement on Form
S-3 (the "Registration Statement"), to be filed on the date hereof by CMS Energy
Corporation, a Michigan corporation (the "Company") and the CMS Trusts with the
Securities and Exchange Commission (the "Commission"). The Registration
Statement relates to, among other things, the issuance and sale from time to
time pursuant to Rule 415 of the General Rules and Regulations promulgated under
the Securities Act of 1933, as amended (the "Act"), of the trust preferred
securities (the "Preferred Securities") of each of the CMS Trusts.

                  The Preferred Securities of each CMS Trust are to be issued
pursuant to the Amended and Restated Trust Agreement of such CMS Trust (each a
"Trust Agreement" and, collectively, the "Trust Agreements"), each such Trust
Agreement





CMS Energy Corporation
June 3, 2005
Page 2



being among the Company, as sponsor, The Bank of New York as property trustee
(the "Property Trustee"), The Bank of New York (Delaware), as Delaware trustee
and Thomas J. Webb, Michael D. Van Heimert and Laura L. Mountcastle,
administrative trustees.

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

                  In connection with this opinion, we have examined originals or
copies, certified or otherwise identified to our satisfaction, of (i) the form
of Registration Statement; (ii) the certificates of trust of each of the CMS
Trusts (the "Certificates of Trust") as filed with the Secretary of State of the
State of Delaware on December 1, 2000; (iii) the form of the Trust Agreement of
each of the CMS Trusts (including the designation of the terms of the Preferred
Securities annexed thereto); (iv) the form of the Preferred Securities of each
of the CMS Trusts and (v) certain resolutions of the Board of Directors of the
Company. We have also examined originals or copies, certified or otherwise
identified to our satisfaction, of such other documents, certificates and
records as we have deemed necessary or appropriate as a basis for the opinions
set forth herein.

                  In our examination, we have assumed the legal capacity of all
natural persons, the genuineness of all signatures, the authenticity of all
documents submitted to us as originals, the conformity to original documents of
all documents submitted to us as certified, conformed, photostatic or facsimile
copies and the authenticity of the originals of such copies. In making our
examination of executed documents or documents to be executed, we have assumed
that the parties thereto, other than the CMS Trusts, had or will have the power,
corporate or other, to enter into and perform all obligations thereunder and
have also assumed the due authorization by all requisite action, corporate or
other, and execution and delivery by such parties of such documents and that
such documents constitute valid and binding obligations of such parties. We have
also assumed that the Trust Agreement of each CMS Trust, and the Preferred
Securities of each CMS Trust, will be executed in substantially the form
reviewed by us. In addition, we have assumed that the terms of the Offered
Preferred Securities (as defined below) will have been established so as not to
violate, conflict with or constitute a default under (i) any agreement or
instrument to which the Company or any of the CMS Trusts or their respective
property is subject; (ii) any law, rule, or regulation to which the Company or
any of the CMS Trusts is subject; (iii) any judicial or administrative order or
decree of any governmental authority or (iv) any consent, approval, license,
authorization or validation of, or filing, recording or registration with any





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June 3, 2005
Page 3



governmental authority. As to any facts material to the opinions expressed
herein that were not independently established or verified, we have relied upon
oral or written statements and representations of officers, trustees and other
representatives of the Company, the CMS Trusts and others.

                  We do not express any opinion as to the laws of any
jurisdiction other than the Business Trust Act of the State of Delaware. The
Offered Preferred Securities may be issued from time to time on a continuous
basis, and this opinion is limited to the Business Trust Act of the State of
Delaware as in effect on the date hereof, which law is subject to change with
possible retroactive effect.

                  Based on and subject to the foregoing and to the other
qualifications and limitations set forth herein, we are of the opinion that the
Preferred Securities of each CMS Trust to be offered pursuant to the
Registration Statement (the "Offered Preferred Securities"), when (i) the
Registration Statement, as finally amended (including all necessary
post-effective amendments), has become effective under the Act; (ii) an
appropriate prospectus with respect to the Offered Preferred Securities has been
prepared, delivered and filed in compliance with the Act and the applicable
rules and regulations thereunder; (iii) the Trust Agreement of such CMS Trust
has been duly executed and delivered by the parties thereto; (iv) the terms of
the Offered Preferred Securities have been established in accordance with the
Trust Agreement; (v) the Offered Preferred Securities have been issued, executed
and authenticated in accordance with the Trust Agreement and delivered and paid
for in the manner contemplated in the Registration Statement or any prospectus
relating thereto and (vi) if the Offered Preferred Securities are to be sold
pursuant to a firm commitment underwritten offering, the underwriting agreement
with respect to the Offered Preferred Securities has been duly authorized,
executed and delivered by the applicable CMS Trust and the other parties
thereto, the Offered Preferred Securities will be duly authorized for issuance
and will be validly issued, fully paid and nonassessable, representing undivided
beneficial interests in the assets of such CMS Trust. We bring to your
attention, however, that the holders of the Offered Preferred Securities may be
obligated, pursuant to the Trust Agreement of such CMS Trust, to (i) provide
indemnity and/or security in connection with, and pay taxes or governmental
charges arising from, transfers of Offered Preferred Securities and (ii) provide
security and indemnity in connection with the requests of, or directions to, the
Property Trustee of such CMS Trust to exercise its rights and powers under the
Trust Agreement of such CMS Trust.







CMS Energy Corporation
June 3, 2005
Page 4



                  We hereby consent to the filing of this opinion with the
Commission as an exhibit to the Registration Statement. We also consent to the
use of our name under the heading "Legal Opinions" in the base prospectus
included in the Registration Statement. In giving this consent, we do not hereby
admit that we are within the category of persons whose consent is required under
Section 7 of the Act or the rules and regulations of the Commission promulgated
thereunder. This opinion is expressed as of the date hereof unless otherwise
expressly stated and we disclaim any undertaking to advise you of any subsequent
changes of the facts stated or assumed herein or of any subsequent changes in
applicable law.

                                        Very truly yours,


                                        /s/ Skadden, Arps, Slate, Meagher &
                                        Flom LLP