Exhibit 99 Form 4 Joint Filer Information Name: Synergy Venture Partners, LLC Address: 1350 Bayshore Highway, Suite 920 Burlingame, CA 94010 Designated Filer: Synergy Life Science Partners, L.P. Issuer & Ticker Symbol: iRhythm Technologies, Inc. (IRTC) Date of Event Requiring Statement: October 25, 2016 Signature: /s/ William N. Starling, Jr., Synergy Venture Partners, LLC, as general partner of Synergy Life Science Partners, L.P. Name: Mudit Jain Address: 1350 Bayshore Highway, Suite 920 Burlingame, CA 94010 Designated Filer: Synergy Life Science Partners, L.P. Issuer & Ticker Symbol: iRhythm Technologies, Inc. (IRTC) Date of Event Requiring Statement: October 25, 2016 Signature: /s/ Mudit Jain, as manager of Synergy Venture Partners, LLC Name: Richard Stack Address: 1350 Bayshore Highway, Suite 920 Burlingame, CA 94010 Designated Filer: Synergy Life Science Partners, L.P. Issuer & Ticker Symbol: iRhythm Technologies, Inc. (IRTC) Date of Event Requiring Statement: October 25, 2016 Signature: /s/ Richard Stack, as manager of Synergy Venture Partners, LLC