X0306 4 2016-10-25 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 1 0 Common Stock 2016-10-25 4 C 0 1716589 A 1716589 I See Footnote Common Stock 2016-10-25 4 P 0 25000 17.00 A 1741589 I See Footnote Series C Convertible Preferred Stock 2016-10-25 4 C 0 610136 0.00 D Common Stock 1370887 0 I See Footnote Series D Convertible Preferred Stock 2016-10-25 4 C 0 190154 0.00 D Common Stock 190154 0 I See Footnote Series E Convertible Preferred Stock 2016-10-25 4 C 0 155548 0.00 D Common Stock 155548 0 I See Footnote Series D Preferred Stock Warrant (Right to Buy) 0.001 2016-10-25 4 C 0 72389 0.00 D 2012-11-01 2019-11-01 Common Stock 72389 0 I See Footnote The Series C Convertible Preferred Stock converted into Common Stock on a 2.24685484-for-1 basis and had no expiration date. The Series D Convertible Preferred Stock converted into Common Stock on a 1-for-1 basis and had no expiration date. The Series E Convertible Preferred Stock converted into Common Stock on a 1-for-1 basis and had no expiration date. Reflects 5.882698 for 1 reverse stock split which became effective on October 5, 2016. 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. /s/ Craig L. Slutzkin, attorney-in-fact, Craig L. Slutzkin, attorney-in-fact for Vijay K. Lathi 2016-10-25