UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM 10-K/A

(Amendment No. 2)

(Mark One)

For the fiscal year ended December 31, 2015

or

For the transition period from                     to                    

Commission file number: 001-36536

CAREDX, INC.

(Exact name of registrant as specified in its charter)

3260 Bayshore Boulevard

Brisbane, California 94005

(Address of principal executive offices and zip code)

(415) 287-2300

(Registrant’s telephone number, including area code)

Securities registered pursuant to Section 12(b) of the Act:

Securities registered pursuant to Section 12(g) of the Act: None

Indicate by check mark if the registrant is a well-known seasoned issuer, as defined in Rule 405 of the Securities Act.    Yes ☐    No ☒

Indicate by check mark if the registrant is not required to file reports pursuant to Section 13 or 15(d) of the Act.    Yes ☐    No ☒

Indicate by check mark whether the registrant (1) has filed all reports required to be filed by Section 13 or 15(d) of the Securities Exchange Act of 1934 during the preceding 12 months (or for such shorter period that the registrant was required to file such reports), and (2) has been subject to such filing requirements for the past 90 days.    Yes ☒    No ☐

Indicate by check mark whether the registrant has submitted electronically and posted on its corporate Web site, if any, every Interactive Data File required to be submitted and posted pursuant to Rule 405 of Regulation S-T during the preceding 12 months (or for such shorter period that the registrant was required to submit and post such files)    Yes ☒    No ☐

Indicate by check mark if disclosure of delinquent filers pursuant to Item 405 of Regulation S-K is not contained herein, and will not be contained, to the best of registrant’s knowledge, in definitive proxy or information statements incorporated by reference in Part III of this Form 10-K/A or any amendment to this Form 10-K/A.    ☒

Indicate by check mark whether the registrant is a large accelerated filer, an accelerated filer, a non-accelerated filer, or a smaller reporting company. See the definitions of “large accelerated filer,” “accelerated filer,” and “smaller reporting company” in Rule 12b-2 of the Exchange Act (Check one).

Indicate by check mark whether the registrant is a shell company (as defined in Rule 12b-2 of the Exchange Act).    Yes ☐    No ☒

The aggregate market value of the voting and non-voting common equity held by non-affiliates of the registrant, based on the closing price of a share of the registrant’s common stock on June 30, 2015 as reported by The NASDAQ Global Market on such date was approximately $48,622,431. Shares of the registrant’s common stock held by each executive officer, director and holder of 10% or more of the outstanding common stock have been excluded in that such persons may be deemed to be affiliates. This calculation does not reflect a determination that certain persons are affiliates of the registrant for any other purpose.

The number of shares of the registrant’s Common Stock outstanding as of February 29, 2016 was 11,966,899.

Explanatory Note

CareDx, Inc. (the “Company”) is filing this Amendment No. 2 (“Amendment No. 2”) to its Form 10-K for the fiscal year ended December 31, 2015 (the “Original Form 10-K”), as amended by Amendment No. 1 to the Annual Report filed with the Securities and Exchange Commission on April 25, 2016 (“Amendment No. 1”), to correct an inadvertent omission of certain language from paragraph 4 of the certification of its Chief Executive Officer filed as Exhibit 31.1 and the certification of its Chief Financial Officer filed as Exhibit 31.2 to the Original Form 10-K.

This Amendment No. 2 should be read in conjunction with the Original Form 10-K and Amendment No. 1, which continue to speak as of the date of the Original Form 10-K. Other than as specifically set forth herein, this Amendment No. 2 does not modify or update disclosures in the Original Form 10-K or Amendment No. 1. Accordingly, this Amendment No. 2 does not reflect events occurring after the filing of the Original Form 10-K or the filing of Amendment No. 1 or modify or update any related or other disclosures.

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 thereunto duly authorized.

EXHIBIT INDEX