This Amendment No. 3 (“Amendment No. 3”) amends and supplements the
Tender Offer Statement on Schedule TO filed with the Securities and Exchange Commission on January 9, 2020 (together with any amendments or supplements thereto, the “Schedule TO”) by (i) Denali Merger Sub, Inc., a Michigan
corporation (“Purchaser”) and a direct wholly owned subsidiary of UnitedHealth Group Incorporated, a Delaware corporation (“UnitedHealth Group”), and (ii) UnitedHealth Group. The Schedule TO relates to the offer by Purchaser
to purchase all outstanding shares (the “Shares”) of common stock, no par value (the “Common Stock”), of Diplomat Pharmacy, Inc., a Michigan corporation (“Diplomat”), at a price of $4.00 per Share, net to the seller in
cash (the “Offer Price”), without interest and subject to any required tax withholding, on the terms and subject to the conditions described in the Offer to Purchase, dated January 9, 2020 (together with any amendments or supplements
thereto, the “Offer to Purchase”), and the accompanying Letter of Transmittal (together with any amendments or supplements thereto, the “Letter of Transmittal,” and, together with the Offer to Purchase and other related
materials, the “Offer”), copies of which are attached to the Schedule TO as Exhibits (a)(1)(A) and (a)(1)(B), respectively.
Except as otherwise set forth in this Amendment No. 3, the information set forth in the Schedule TO remains unchanged and is incorporated
herein by reference to the extent relevant to the items in this Amendment No. 3. Capitalized terms used but not defined herein have the meanings assigned to such terms in the Offer to Purchase. This Amendment No. 3 should be read together
with the Schedule TO.
Items 1 through 9 and Item 11.
The Offer to Purchase and Items 1 through 9 and Item 11 of the Schedule TO, to the extent such Items incorporate by reference the information
contained in the Offer to Purchase, are hereby amended and supplemented to include the following:
“The Offer and withdrawal rights
expired as scheduled at 12:01 a.m., New York City time, on Friday, February 7, 2020. The Depositary advised UnitedHealth Group and Purchaser that, as of the expiration time of the Offer, 61,203,549 Shares (not including 394,405 Shares tendered
by notice of guaranteed delivery for which Shares have not yet been delivered) had been validly tendered and not properly withdrawn pursuant to the Offer, which represented approximately 80.53% of the total number of outstanding Shares. Accordingly,
the number of Shares validly tendered into the Offer and not properly withdrawn satisfied the Minimum Tender Condition. All conditions to the Offer have been satisfied. No later than February 10, 2020, Purchaser will accept for payment, and
following such acceptance will promptly pay for, all Shares validly tendered into and not properly withdrawn from the Offer.
Following
the consummation of the Offer, pursuant to the terms and conditions of the Merger Agreement and in accordance with Section 703a(3) of the MBCA, UnitedHealth Group intends to merge Purchaser with and into Diplomat, with Diplomat surviving as a
direct wholly owned subsidiary of UnitedHealth Group, without a vote of Diplomat shareholders. Each Share issued and outstanding immediately prior to the Effective Time, other than Shares that as of the Effective Time are (i) owned by
UnitedHealth Group, Purchaser or any wholly owned subsidiary thereof or (ii) owned by Diplomat or held in Diplomat’s treasury, will be automatically converted into the right to receive the Offer Price in cash, without interest and subject
to any required tax withholding.
Following the Merger, the Shares will be delisted and will cease trading on the NYSE and will be
deregistered under the Exchange Act.”