CDW : 2021 Proxy Card and Notice

CDW CORPORATION

75 TRI-STATE INTERNATIONAL LINCOLNSHIRE, IL 60069

SCAN TO w

VIEW MATERIALS &VOTE

VOTE BY INTERNET

Before The Meeting - Go to www.proxyvote.comor scan the QR Barcode above

Use the Internet to transmit your voting instructions and for electronic delivery of information up until 11:59 p.m. Eastern Time the day before the cut-off date or meeting date. Have your proxy card in hand when you access the web site and follow the instructions to obtain your records and to create an electronic voting instruction form.

During The Meeting - Go to www.virtualshareholdermeeting.com/CDW2021

You may attend the meeting via the Internet and vote during the meeting. Have the information that is printed in the box marked by the arrow available and follow the instructions.

VOTE BY PHONE - 1-800-690-6903

Use any touch-tone telephone to transmit your voting instructions up until 11:59 p.m. Eastern Time the day before the cut-off date or meeting date. Have your proxy card in hand when you call and then follow the instructions.

VOTE BY MAIL

Mark, sign and date your proxy card and return it in the postage-paid envelope we have provided or return it to Vote Processing, c/o Broadridge, 51 Mercedes Way, Edgewood, NY 11717.

TO VOTE, MARK BLOCKS BELOW IN BLUE OR BLACK INK AS FOLLOWS:

D43752-P49106	KEEP THIS PORTION FOR YOUR RECORDS
THIS PROXY CARD IS VALID ONLY WHEN SIGNED AND DATED.	DETACH AND RETURN THIS PORTION ONLY

CDW CORPORATION

The Board of Directors recommends you vote FOR the following ten Directors (Term to Expire at 2022 Annual Meeting):

1. Election of Directors

Nominees:

1a. Virginia C. Addicott

1b. James A. Bell

1c. Lynda M. Clarizio

1d. Paul J. Finnegan

1e. Anthony R. Foxx

1f. Christine A. Leahy

1g. Sanjay Mehrotra

1h. David W. Nelms

1i. Joseph R. Swedish

1j. Donna F. Zarcone

HOUSEHOLDING ELECTION- please indicate if you consent to receive certain future investor communications in a single package per household.

For Against Abstain

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Yes No

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The Board of Directors recommends you vote FOR proposals 2, 3, 4, 5, 6 and 7:

1. To approve, on an advisory basis, named executive officer compensation.
2. To ratify the selection of Ernst & Young LLP as the Company's independent registered public accounting firm for the year ending December 31, 2021.
3. To approve the amendment to the Company's Certificate of Incorporation to eliminate the supermajority voting requirement in Article Eleven and to make certain non-substantive changes.
4. To approve the amendment to the Company's Certificate of Incorporation to eliminate the obsolete competition and corporate opportunity provision.
5. To approve the CDW Corporation 2021 Long-Term Incentive Plan.
6. To approve the amendment to the CDW Corporation Coworker Stock Purchase Plan.

For Against Abstain

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Signature [PLEASE SIGN WITHIN BOX]	Date		Signature (Joint Owners)	Date

Important Notice Regarding the Availability of Proxy Materials for the Annual Meeting:

The Notice and Proxy Statement and Annual Report are available at www.proxyvote.com.

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CDW CORPORATION

Annual Meeting of Stockholders

May 20, 2021

This proxy is solicited by the Board of Directors

The stockholder(s) hereby appoint(s) Collin B. Kebo and Frederick J. Kulevich, or either of them, as proxies, each with the power to appoint his substitute, and hereby authorize(s) them to represent and to vote, as designated on the reverse side of this ballot, all of the shares of Common Stock of CDW Corporation that the stockholder(s) is/are entitled to vote at the Annual Meeting of Stockholders to be held at 7:30 a.m., Central Time, on May 20, 2021, to be held virtually at: www.virtualshareholdermeeting.com/CDW2021, and any adjournment or postponement thereof.

THIS PROXY, WHEN PROPERLY EXECUTED, WILL BE VOTED AS DIRECTED BY THE STOCKHOLDER(S). IF NO SUCH DIRECTIONS ARE MADE, THIS PROXY WILL BE VOTED FOR THE ELECTION OF EACH OF THE NOMINEES LISTED ON THE REVERSE SIDE FOR THE BOARD OF DIRECTORS AND FOR PROPOSALS 2, 3, 4, 5, 6 AND 7. IF ANY OTHER MATTERS PROPERLY COME BEFORE THE MEETING, OR ANY ADJOURNMENT THEREOF, THE PERSON(S) NAMED ABOVE WILL VOTE IN THEIR DISCRETION. THIS PROXY REVOKES ANY PROXY PREVIOUSLY GIVEN.

Continued and to be signed on reverse side

Your Vote Counts!

CDW CORPORATION

2021 Annual Meeting

Vote by May 19, 2021

11:59 PM ET

CDW CORPORATION

75 TRI-STATE INTERNATIONAL LINCOLNSHIRE, IL 60069

D43815-P49106

You invested in CDW CORPORATION and it's time to vote!

You have the right to vote on proposals being presented at the Annual Meeting. This is an important notice regarding the availability of proxy material for the stockholder meeting to be held on May 20, 2021.

Get informed before you vote

View the Notice and Proxy Statement and Annual Report online OR you can receive a free paper or email copy of the material(s) by requesting prior to May 6, 2021. If you would like to request a copy of the material(s) for this and/or future stockholder meetings, you may (1) visit www.ProxyVote.com, (2) call 1-800-579-1639 or (3) send an email to [e-mail]. If sending an email, please include your control number (indicated below) in the subject line. Unless requested, you will not otherwise receive a paper or email copy.

For complete information and to vote, visit www.ProxyVote.com

Control #

Smartphone users		Vote Virtually at the Meeting*
Point your camera here and		May 20, 2021
vote without entering a		7:30 a.m. Central Time
control number		Virtually at:
		www.virtualshareholdermeeting.com/CDW2021

*Please check the meeting materials for any special requirements for meeting attendance.

V1

Vote at www.ProxyVote.com

THIS IS NOT A VOTABLE BALLOT

This is an overview of the proposals being presented at the upcoming stockholder meeting. Please follow the instructions on the reverse side to vote these important matters.

Voting Items	Board
Recommends
1.	Election of Directors
	Nominees:
1a.	Virginia C. Addicott	For
1b.	James A. Bell	For
1c.	Lynda M. Clarizio	For
1d.	Paul J. Finnegan	For
1e.	Anthony R. Foxx	For
1f.	Christine A. Leahy	For
1g.	Sanjay Mehrotra	For
1h.	David W. Nelms	For
1i.	Joseph R. Swedish	For
1j.	Donna F. Zarcone	For
2.	To approve, on an advisory basis, named executive officer compensation.	For
3.	To ratify the selection of Ernst & Young LLP as the Company's independent registered public accounting firm for the	For
	year ending December 31, 2021.
4.	To approve the amendment to the Company's Certificate of Incorporation to eliminate the supermajority voting	For
	requirement in Article Eleven and to make certain non-substantive changes.

5. To approve the amendment to the Company's Certificate of Incorporation to eliminate the obsolete competition and For corporate opportunity provision.

6.	To approve the CDW Corporation 2021 Long-Term Incentive Plan.	For
7.	To approve the amendment to the CDW Corporation Coworker Stock Purchase Plan.	For

NOTE: Such other business as may properly come before the meeting or any adjournment thereof.

Prefer to receive an email instead? While voting on www.ProxyVote.com, be sure to click "Sign up for E-delivery".

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