SEC FORM 3 SEC Form 3
FORM 3 UNITED STATES SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

INITIAL STATEMENT OF BENEFICIAL OWNERSHIP OF SECURITIES

Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934
or Section 30(h) of the Investment Company Act of 1940
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1. Name and Address of Reporting Person*
MADISON DEARBORN PARTNERS LLC

(Last) (First) (Middle)
C/O MADISON DEARBORN PARTNERS, LLC
70 W. MADISON STREET, SUITE 4600

(Street)
CHICAGO IL 60602

(City) (State) (Zip)
2. Date of Event Requiring Statement (Month/Day/Year)
06/26/2013
3. Issuer Name and Ticker or Trading Symbol
CDW Corp [ CDW ]
4. Relationship of Reporting Person(s) to Issuer
(Check all applicable)
Director X 10% Owner
Officer (give title below) Other (specify below)
5. If Amendment, Date of Original Filed (Month/Day/Year)
6. Individual or Joint/Group Filing (Check Applicable Line)
Form filed by One Reporting Person
X Form filed by More than One Reporting Person
Table I - Non-Derivative Securities Beneficially Owned
1. Title of Security (Instr. 4) 2. Amount of Securities Beneficially Owned (Instr. 4) 3. Ownership Form: Direct (D) or Indirect (I) (Instr. 5) 4. Nature of Indirect Beneficial Ownership (Instr. 5)
Common Stock, par value $0.01 66,739,156 I See Footnotes(1)(2)(3)(4)
Table II - Derivative Securities Beneficially Owned
(e.g., puts, calls, warrants, options, convertible securities)
1. Title of Derivative Security (Instr. 4) 2. Date Exercisable and Expiration Date (Month/Day/Year) 3. Title and Amount of Securities Underlying Derivative Security (Instr. 4) 4. Conversion or Exercise Price of Derivative Security 5. Ownership Form: Direct (D) or Indirect (I) (Instr. 5) 6. Nature of Indirect Beneficial Ownership (Instr. 5)
Date Exercisable Expiration Date Title Amount or Number of Shares
1. Name and Address of Reporting Person*
MADISON DEARBORN PARTNERS LLC

(Last) (First) (Middle)
C/O MADISON DEARBORN PARTNERS, LLC
70 W. MADISON STREET, SUITE 4600

(Street)
CHICAGO IL 60602

(City) (State) (Zip)
1. Name and Address of Reporting Person*
Madison Dearborn Capital Partners V - A L P

(Last) (First) (Middle)
C/O MADISON DEARBORN PARTNERS, LLC
70 W. MADISON STREET, SUITE 4600

(Street)
CHICAGO IL 60602

(City) (State) (Zip)
1. Name and Address of Reporting Person*
Madison Dearborn Capital Partners V - C L P

(Last) (First) (Middle)
C/O MADISON DEARBORN PARTNERS, LLC
70 W. MADISON STREET, SUITE 4600

(Street)
CHICAGO IL 60602

(City) (State) (Zip)
1. Name and Address of Reporting Person*
MADISON DEARBORN CAPITAL PARTNERS V EXECUTIVE-A L P

(Last) (First) (Middle)
C/O MADISON DEARBORN PARTNERS, LLC
70 W. MADISON STREET, SUITE 4600

(Street)
CHICAGO IL 60602

(City) (State) (Zip)
1. Name and Address of Reporting Person*
MDCP Co-Investors (CDW) LP

(Last) (First) (Middle)
C/O MADISON DEARBORN PARTNERS, LLC
70 W. MADISON STREET, SUITE 4600

(Street)
CHICAGO IL 60602

(City) (State) (Zip)
1. Name and Address of Reporting Person*
MADISON DEARBORN PARTNERS V-A&C, L.P.

(Last) (First) (Middle)
C/O MADISON DEARBORN PARTNERS, LLC
70 W. MADISON STREET, SUITE 4600

(Street)
CHICAGO IL 60602

(City) (State) (Zip)
1. Name and Address of Reporting Person*
MENCOFF SAMUEL M

(Last) (First) (Middle)
C/O MADISON DEARBORN PARTNERS, LLC
70 W. MADISON STREET, SUITE 4600

(Street)
CHICAGO IL 60602

(City) (State) (Zip)
Explanation of Responses:
1. Consists of 43,565,137 shares held directly by Madison Dearborn Capital Partners V-A, L.P. ("MDP A"), 11,557,077 shares held directly by Madison Dearborn Capital Partners V-C, L.P. ("MDP C"), 437,743 shares held directly by Madison Dearborn Capital Partners V Executive-A, L.P. ("MDP Exec") and 11,179,199 shares held directly by MDCP Co-Investors (CDW), L.P. ("MDP Co-Investor"). Madison Dearborn Partners V-A&C, L.P. ('MDP V') is the general partner of MDP A, MDP C, MDP Exec and MDP Co-Investor. Madison Dearborn Partners, LLC ('MDP') is the general partner of MDP V. As the sole members of a limited partner committee of MDP V that has the power, acting by majority vote, to vote or dispose of the shares directly held by MDP A, MDP C, MDP Exec and MDP Co-Investor, Paul J. Finnegan and (Continued in footnote 2)
2. Samuel M. Mencoff may be deemed to have shared voting and investment power over such shares. Each of Messrs. Finnegan and Mencoff and MDP V hereby disclaims any beneficial ownership of any shares held by MDP A, MDP C, MDP Exec and MDP Co-Investor except to the extent of his pecuniary interest therein.
3. Mr. Mencoff has an indirect pecuniary interest in the shares of CDW Corporation's common stock held of record by the various MDP funds described above through his investment in MDP V. Each of MDP A, MDP C, MDP Exec and MDP Co-Investor and Mr. Mencoff may be deemed to share beneficial ownership of the reported securities and expressly disclaims beneficial ownership of such shares except to the extent of its or his pecuniary interest therein.
4. Mr. Finnegan has separately filed a Form 3.
Remarks:
Exhibit List: Exhibit 24 - Power of Attorney
Madison Dearborn Partners, LLC by /s/ James S. Rowe, Attorney-in-Fact 06/26/2013
Madison Dearborn Capital Partners V-A, L.P. by /s/ James S. Rowe, Attorney-in-Fact 06/26/2013
Madison Dearborn Capital Partners V-C, L.P. by /s/ James S. Rowe, Attorney-in-Fact 06/26/2013
Madison Dearborn Capital Partners V Executive-A, L.P. by /s/ James S. Rowe, Attorney-in-Fact 06/26/2013
MDCP Co-Investors (CDW), L.P. by /s/ James S. Rowe, Attorney-in-Fact 06/26/2013
Madison Dearborn Partners V - A&C, L. P. by /s/ James S. Rowe, Attorney-in-Fact 06/26/2013
Samuel M. Mencoff by /s/ James S. Rowe, Attorney-in-Fact 06/26/2013
** Signature of Reporting Person Date
Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.
* If the form is filed by more than one reporting person, see Instruction 5 (b)(v).
** Intentional misstatements or omissions of facts constitute Federal Criminal Violations See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).
Note: File three copies of this Form, one of which must be manually signed. If space is insufficient, see Instruction 6 for procedure.
Persons who respond to the collection of information contained in this form are not required to respond unless the form displays a currently valid OMB Number.
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                                                    POWER OF ATTORNEY

        KNOW ALL PERSONS BY THESE PRESENTS, that the undersigned hereby makes, constitutes and appoints each of Mark B.
Tresnowski, Annie S. Terry and James S. Rowe signing singly, as the undersigned's true and lawful attorney-in-fact, with
full power and authority as hereinafter described on behalf of and in the name, place and stead of the undersigned to:

        (1)     prepare, execute, acknowledge, deliver and file Forms 3, 4 and 5 (including any amendments thereto) with
respect to the securities of CDW Corporation, a Delaware corporation (the "Company"), with the U.S. Securities and
Exchange Commission (the "Commission") and any national securities exchanges or similar authority, as considered
necessary or advisable under Section 16(a) of the Securities Exchange Act of 1934 and the rules and regulations
promulgated thereunder, as amended from time to time (the "Exchange Act");

        (2)     seek or obtain, as the undersigned's representative and on the undersigned's behalf, information on
transactions in the Company's securities from any third party, including brokers, employee benefit plan administrators
and trustees, and the undersigned hereby authorizes any such person to release any such information
 to the undersigned
and approves and ratifies any such release of information; and

        (3)     perform any and all other acts which in the discretion of such attorneys-in-fact are necessary or
desirable for and on behalf of the undersigned in connection with the foregoing.

        The undersigned acknowledges that:

        (1)     this Power of Attorney authorizes, but does not require, each such attorney-in-fact to act in their
discretion on information provided to such attorney-in-fact without independent verification of such information;

        (2)     any documents prepared and/or executed by any of the attorneys-in-fact on behalf of the
undersigned pursuant to this Power of Attorney will be in such form and will contain such information and disclosure as
such attorney-in-fact, in his or her discretion, deems necessary or desirable;

        (3)     neither the Company nor any of the attorneys-in-fact assumes (i) any liability for the undersigned's
responsibility to comply with the requirements of the Exchange Act, (ii) any liability of the undersigned for any
failure to comply with such requirements, or (iii) any obligation or liability of the undersigned for profit
disgorgement under Section 16(b) of the Exchange Act; and

        (4)     this Power of Attorney does not relieve the undersigned from responsibility for compliance with the
undersigned's obligations under the Exchange Act, including without limitation the reporting requirements under Section
16 of the Exchange Act.

        The undersigned hereby gives and grants each of the foregoing attorneys-in-fact full power and authority to do
and perform all and every act and thing whatsoever requisite, necessary or appropriate to be done in and about the
foregoing matters as fully to all intents and purposes as the undersigned might or could do if present, with full power
of substitution and revocation, hereby ratifying all that such attorney-in-fact, or such attorney-in-fact's substitute
or substitutes, of, for and on behalf of the undersigned, shall lawfully do or cause to be done by virtue of this Power
of Attorney.

        This Power of Attorney shall remain in full force and effect until the earlier of (i) the date on which the
undersigned is no longer required to file Forms 3, 4 or 5 with respect to the undersigned's holdings of and transactions
in securities issued by the Company; (ii) as to the appointment of Mark B. Tresnowski and Annie S. Terry, upon his or
her respective resignation or termination as an employee of Madison Dearborn Partners, LLC; (iii) as to the appointment
of James S. Rowe, upon his resignation or removal as a partner of Kirkland & Ellis LLP; and (iv) revocation of this
Power of Attorney by the undersigned in a signed writing delivered to each of such attorneys-in-fact. This Power of
Attorney may be filed with the Commission as a conforming statement of the authority granted herein.

                                                     * * * * *

        IN WITNESS WHEREOF, the undersigned has caused this Power of Attorney to be executed as of this 26th day of
June, 2013.

MADISON DEARBORN PARTNERS, LLC

By:  /s/ Robin P. Selati
     --------------------------------------
     Name: Robin P. Selati
     Its: Managing Director

MADISON DEARBORN CAPITAL PARTNERS V-A, L.P.

By:  Madison Dearborn Partners V-A&C, L.P.
Its: General Partner

By:  Madison Dearborn Partners, LLC
Its: General Partner

By:   /s/ Robin P. Selati
     -------------------------------------
     Name:Robin P. Selati
     Its:Managing Director

MADISON DEARBORN CAPITAL PARTNERS V-C, L.P.

By:  Madison Dearborn Partners V-A&C, L.P.
Its: General Partner

By:  Madison Dearborn Partners, LLC
Its: General Partner

By:  /s/ Robin P. Selati
     -------------------------------------
     Name: Robin P. Selati
     Its: Managing Director

MADISON DEARBORN CAPITAL PARTNERS V EXECUTIVE-A, L.P.

By:  Madison Dearborn Partners V-A&C, L.P.
Its: General Partner

By:  Madison Dearborn Partners, LLC
Its: General Partner

By:  /s/ Robin P. Selati
     -------------------------------------
     Name: Robin P. Selati
     Its: Managing Director

MDCP Co-Investors (CDW), L.P.

By:  Madison Dearborn Partners V-A&C, L.P.
Its: General Partner

By:  Madison Dearborn Partners, LLC
Its: General Partner

By:  /s/ Robin P. Selati
     -------------------------------------
     Name: Robin P. Selati
     Its: Managing Director

MADISON DEARBORN PARTNERS V - A&C, L.P.

By:  Madison Dearborn Partners, LLC
Its: General Partner

By:  /s/ Robin P. Selati
     -------------------------------------
     Name: Robin P. Selati
     Its: Managing Director

SAMUEL M. MENCOFF
/s/ Samuel M. Mencoff
------------------------------------------