UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM 8-K

CURRENT REPORT

Pursuant to Section 13 or 15(d)

of the Securities Exchange Act of 1934

Date of Report (Date of earliest event reported): June 12, 2013

CDW CORPORATION

(Exact name of registrant as specified in its charter)

Registrant’s telephone number, including area code: (847) 465-6000

None

(Former name or former address, if changed since last report)

Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation of the registrant under any of the following provisions:

On June 12, 2013, in anticipation of the planned initial public offering of common stock (the “Offering”) of CDW Corporation (the “Company”), the Company entered into a termination agreement (the “Termination Agreement”) with Madison Dearborn Partners V-B, L.P. (“MDP”), Providence Equity Partners L.L.C. (“PEP,” and together with MDP, the “Sponsors”) and CDW LLC that will become effective upon the closing of the Offering. Upon the closing of the Offering and in exchange for the termination of the management services agreement with affiliates of the Sponsors pursuant to which such affiliates currently provide the Company with management, consulting, financial and other advisory services, the Company will pay to MDP a fee in the amount of $12,936,880 and will pay to PEP a fee in the amount of $11,463,120.

The foregoing is only a summary of the material terms of the Termination Agreement and does not purport to be complete, and is qualified in its entirety by reference to the Termination Agreement, a copy of which is filed as Exhibit 10.1 hereto and incorporated by reference herein.

CDW Corporation 2013 Senior Management Incentive Plan

On June 12, 2013, in anticipation of the Offering, the Company established the CDW Corporation 2013 Senior Management Incentive Plan (the “2013 SMIP”) to assist the Company in attracting, motivating and retaining officers and other senior managers who have significant responsibility for growth and long-term success by providing incentive awards that ensure a strong pay-for-performance linkage for such officers and senior managers.

The material terms of the 2013 SMIP are as follows:

The foregoing is only a summary of the material terms of the 2013 SMIP and does not purport to be complete, and is qualified in its entirety by reference to the 2013 SMIP, a copy of which is filed as Exhibit 10.2 hereto and incorporated by reference herein.

CDW Corporation 2013 Long-Term Incentive Plan

On June 12, 2013, in anticipation of the Offering, the Company adopted the CDW Corporation 2013 Long-Term Incentive Plan (the “2013 LTIP”). The purposes of the 2013 LTIP are to align the interests of stockholders and those eligible for awards, to retain officers, directors, employees, and other service providers, and to encourage them to act in the Company’s long term best interests. The 2013 LTIP provides for the grant of incentive stock options, within the meaning of Internal Revenue Code Section 422, nonqualified stock options, stock appreciation rights, restricted stock (including the 3,963,925 shares of restricted stock the Company expects to grant in substitution for unvested B Units of CDW Holdings LLC in connection with the Offering assuming an initial public offering price of $21.50 per share), restricted stock units, bonus stock and performance awards. Officers, directors, employees, consultants, agents and independent contractors who provide services to the Company or to any of its subsidiaries are eligible to receive such awards. The material terms of the 2013 LTIP are as follows:

The foregoing is only a summary of the material terms of the 2013 LTIP and does not purport to be complete, and is qualified in its entirety by reference to the 2013 LTIP, a copy of which is filed as Exhibit 10.3 hereto and incorporated by reference herein.

On June 12, 2013, forms of option and restricted stock award agreements to be used in connection with awards to be made under the 2013 LTIP to certain named executive officers were also approved. Copies of these forms are filed as Exhibits 10.4, 10.5, 10.6 and 10.7 hereto and incorporated by reference herein.

CDW Corporation Coworker Stock Purchase Plan

On June 12, 2013, in anticipation of the Offering, the Company adopted the CDW Corporation Coworker Stock Purchase Plan (the “Purchase Plan”), which is summarized below.

Generally, all coworkers (including those of consolidated subsidiaries, other than those subsidiaries excluded from participation by the board of directors or the Compensation Committee) who have been employed for at least 90 days are eligible to participate in the Purchase Plan. The Purchase Plan permits employees to purchase common stock through payroll deductions during quarterly offerings periods, with the first offering period beginning January 1, 2014. Participants may authorize payroll deductions of a specific percentage of compensation between 1% and 15%, with such deductions being accumulated for quarterly purchase periods beginning on the first business day of each offering period and ending on the last business day of each offering period. Under the terms of the Purchase Plan, the purchase price per share will equal 95% of the fair market value of a share of common stock on

the last business day of each offering period, although the Compensation Committee has discretion to change the purchase price with respect to future offering periods. No employee may participate in an offering period if the employee owns 5% or more of the total combined voting power or value of stock or the stock of any of subsidiaries. No participant may purchase more than 1,250 shares of common stock during any offering period.

1,700,000 shares of common stock, subject to adjustment for stock splits, stock dividends or other changes in capital stock, have been reserved for issuance under the Purchase Plan.

The Purchase Plan will be administered by the Compensation Committee or a designee of the Compensation Committee. The Purchase Plan may be amended by the board of directors or the Compensation Committee but may not be amended without prior stockholder approval to the extent required by Section 423 of the Code.

The foregoing is only a summary of the material terms of the Purchase Plan and does not purport to be complete, and is qualified in its entirety by reference to the Purchase Plan, a copy of which is filed as Exhibit 10.8 hereto and incorporated by reference herein.

RDU Plan

On June 12, 2013, in anticipation of the Offering and the anticipated redemption of senior subordinated exchange notes due 2017 (the “Senior Subordinated Notes”) using a portion of the net proceeds received by the Company from the Offering together with borrowings under CDW LLC’s existing senior secured asset-based revolving credit facility or under an incremental term loan under CDW LLC’s existing senior secured term loan facility, the Company amended the CDW Restricted Debt Unit Plan (the “RDU Plan”) in order to increase the retentive value of the plan, which is summarized below.

The RDU Plan is designed to retain key leaders and focus them on driving the long-term success of the Company. The RDU Plan is an unfunded nonqualified deferred compensation plan. Participants in the RDU Plan receive restricted debt units (“RDUs”) that entitled the participant to a proportionate share of payments under the RDU Plan, determined by dividing the number of RDUs held by the participant by 28,500, which is the total number of RDUs available under the RDU Plan. Each RDU represents $1,000 of face value of the Senior Subordinated Notes.

The RDUs are designed to track two components of the Senior Subordinated Notes, a principal component and an interest component. However, the participants have no rights to the underlying debt. The total amount of compensation available under the RDU Plan is based on these two components. The principal component credits the RDU Plan with an amount equal to $28.5 million face value of the Senior Subordinated Notes (the “debt pool”). Participants vest daily in the principal component during employment on a pro rata basis over the period commencing January 1, 2012 (or, if later, the date of hire or the date of a subsequent RDU grant) through December 31, 2014, unless accelerated. Payment of the principal component on a participant’s vested RDUs under the RDU Plan will be made to participants on October 12, 2017, unless accelerated due to a sale of the Company. The interest component credits the RDU Plan with amounts equal to the interest that would have been earned on the debt pool from March 10, 2010 (or, if later, the date of hire or the date of a subsequent RDU grant) through maturity (October 12, 2017). Under the original terms of the RDU Plan, interest amounts for 2010 and 2011 were deferred until 2012, and thereafter, subject to certain exceptions, interest amounts were to be paid to participants semi-annually on the interest payment dates.

In accordance with the original terms of the plan, the principal component of the RDUs will convert to a cash-denominated pool upon the planned redemption of the Senior Subordinated Notes and continue to vest on a daily basis and to become payable to participants on October 12, 2017, unless payment is accelerated due to a sale of the Company. The planned redemption of the Senior Subordinated Notes will also, per the terms of the RDU Plan, result in holders of RDUs being credited with an additional amount equal to the amount of the prepayment premium that would have been paid on an equivalent amount of Senior Subordinated Notes under the terms of the indenture related to such notes. This additional amount will, like principal, be paid to holders of RDUs on October 12, 2017.

However, as allowed under the original terms of the plan, the accrual of interest credits on the RDUs will cease after the redemption of the Senior Subordinated Notes. Instead, the Compensation Committee intends to give participants the opportunity to share on a pro rata basis in cash retention pools that will be payable to participants who satisfy certain continuing-employment requirements. The aggregate amount of the cash retention pools was determined based on the amount of interest component credits that would have been allocated to the RDUs under the original terms of the plan if the Senior Subordinated Notes had not been redeemed.

The foregoing is only a summary of the material terms of the RDU Plan and does not purport to be complete, and is qualified in its entirety by reference to the amended and restated RDU Plan, a copy of which is filed as Exhibit 10.9 hereto and incorporated by reference herein.

(d) Exhibits

SIGNATURES

Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned hereunto duly authorized.

EXHIBIT INDEX