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

November 20, 2013

Date of Report (Date of earliest event reported)

WEBMD HEALTH CORP.

(Exact name of registrant as specified in its charter)

111 Eighth Avenue

New York, New York 10011

(Address of principal executive offices, including zip code)

(212) 624-3700

(Registrant’s telephone number, including area code)

(Former name or 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 (see General Instruction A.2. below):

To the extent required by Item 1.01 of Form 8-K, the information contained in Item 2.03 of this Current Report is hereby incorporated by reference into this Item 1.01.

On November 20, 2013, the Registrant issued a press release announcing a proposed private placement of Convertible Notes due 2020. A copy of this press release is filed as Exhibit 99.1 to this Current Report. On November 21, 2013, the Registrant issued a press release regarding the pricing of its offer and sale of $300 million aggregate principal amount of 1.50% Convertible Notes due 2020 (the “Notes”), plus up to an additional $50 million principal amount of Notes pursuant to an over-allotment option granted to the initial purchaser of the Notes. A copy of this press release is filed as Exhibit 99.2 to this Current Report.

On November 26, 2013, the Registrant completed the private placement of $300 million aggregate principal amount of the Notes and entered into an Indenture, with respect to the Notes, with The Bank of New York Mellon Trust Company, N.A. A copy of the Indenture (which will contain a copy of the form of the Note) will be filed as Exhibit 4.1 to an amendment to this Current Report. The Notes were issued by the Registrant to an initial purchaser in a private placement pursuant to Section 4(2) of the Securities Act of 1933, as amended (the “Securities Act”), for resale to “qualified institutional buyers” (as defined in, and in reliance on, Rule 144A under the Securities Act) through the initial purchaser. Net proceeds to the Registrant from the sale of the Notes are estimated to be approximately $291.5 million, after the initial purchaser’s discount and estimated expenses. The Registrant intends to use the net proceeds for general corporate purposes, which may include acquisitions, repurchases of its common stock (“Common Stock”), and working capital.

The Notes will mature on December 1, 2020, unless previously repurchased or converted in accordance with their terms prior to such date. Interest on the Notes is payable semiannually on June 1 and December 1 of each year, commencing on June 1, 2014. Under the terms of the Notes, holders may surrender their Notes for conversion into Common Stock at an initial conversion rate of 18.9362 shares of Common Stock per $1,000 principal amount of Notes. This is equivalent to an initial conversion price of approximately $52.81 per share of Common Stock. The initial conversion price represents a premium of approximately 36% over the closing price of the Common Stock on the Nasdaq Global Select Market on November 20, 2013. In the aggregate, the Notes are initially convertible into 5,680,860 shares of Common Stock. The conversion rate may be adjusted under certain circumstances.

Under the terms of the Notes, if the Registrant undergoes certain change of control or other fundamental change transactions prior to the maturity date of the Notes, holders of the Notes will have the right, at their option, to require the Registrant to repurchase some or all of their Notes at a repurchase price equal to 100% of the principal amount of the Notes being repurchased, plus accrued and unpaid interest to, but excluding, the repurchase date.

To the extent required by Item 3.02 of Form 8-K, the information contained in Item 2.03 of this Current Report is hereby incorporated by reference into this Item 3.02.

2

(d) Exhibits. The following exhibits are filed herewith:

3

SIGNATURE

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 thereunto duly authorized.

4

EXHIBIT INDEX