United States securities and exchange commission logo September 1, 2020 Michael Bell Chief Financial Officer CareDx, Inc. 1 Tower Place South San Francisco, California 94080 Re: CareDx, Inc. Form 10-K for the Year Ended December 31, 2019 Filed February 28, 2020 Form 8-K Filed April 30, 2020 File No. 001-36536 Dear Mr. Bell: We have completed our review of your filings. We remind you that the company and its management are responsible for the accuracy and adequacy of their disclosures, notwithstanding any review, comments, action or absence of action by the staff. Sincerely, Division of Corporation Finance Office of Life Sciences cc: Jeff Hartlin