X0306 4 2017-04-26 0 0001388658 iRhythm Technologies, Inc. IRTC 0001340806 Lathi Vijay K C/O NEW LEAF VENTURE PARTNERS 7 TIMES SQUARE, SUITE 3502 NEW YORK NY 10036 1 0 0 0 Common Stock 2017-04-26 4 A 0 1405 0.00 A 1405 D Common Stock 665965 I See Footnote Employee Stock Option (right to buy) 34.61 2017-04-26 4 A 0 3007 0.00 A 2027-04-26 Common Stock 3007 3007 D The reported securities are represented by restricted stock units ("RSUs"), which represents a contingent right to receive shares of IRTC common stock. The RSUs fully vest on April 26, 2018. Represents shares directly beneficially owned by New Leaf Ventures II, L.P. ("NLV II"). The Reporting Person is an individual manager of New Leaf Venture Management II, L.L.C. ("Management II"). Management II is the general partner of New Leaf Venture Associates II, L.P. ("Associates II"). Associates II is the general partner of New Leaf Ventures II, L.P. ("NLV II"). As such, the Reporting Person shares voting and dispositive control with respect to the shares held by NLV II. The Reporting Person disclaims beneficial ownership of the shares held by NLV II, except to the extent of his proportionate pecuniary interest therein. The option vests in twelve equal monthly installments beginning on May 26, 2017. /s/ Craig L. Slutzkin, attorney-in-fact for Vijay K. Lathi 2017-07-07