X0306 4 2016-10-25 1 0001388658 iRhythm Technologies, Inc. IRTC 0001441439 New Leaf Ventures II, L.P. C/O NEW LEAF VENTURE PARTNERS 7 TIMES SQUARE, SUITE 3502 NEW YORK NY 10036 0 0 1 0 0001441563 Delagardelle Jeani C/O NEW LEAF VENTURE PARTNERS, 1200 PARK PLACE, SUITE 300 SAN MATEO CA 94403 0 0 1 0 0001247851 HUNT RONALD C/O NEW LEAF VENTURE PARTNERS, 7 TIMES SQUARE, SUITE 3502 NEW YORK NY 10036 0 0 1 0 0001547100 Ratcliffe Liam C/O NEW LEAF VENTURE PARTNERS, 7 TIMES SQUARE, SUITE 3502 NEW YORK NY 10036 0 0 1 0 0001441858 New Leaf Venture Associates II, L.P. C/O NEW LEAF VENTURE PARTNERS, 7 TIMES SQUARE, SUITE 3502 NEW YORK NY 10036 0 0 1 0 0001441857 New Leaf Venture Management II, L.L.C. C/O NEW LEAF VENTURE PARTNERS, 7 TIMES SQUARE, SUITE 3502 NEW YORK NY 10036 0 0 1 0 0001192212 Chambon Philippe O. C/O NEW LEAF VENTURE PARTNERS, 7 TIMES SQUARE, SUITE 3502 NEW YORK NY 10036 0 0 1 0 Common Stock 2016-10-25 4 C 0 1716589 A 1716589 D Common Stock 2016-10-25 4 P 0 25000 17.00 A 1741589 D Series C Convertible Preferred Stock 2016-10-25 4 C 0 610136 0.00 D Common Stock 1370887 0 D Series D Convertible Preferred Stock 2016-10-25 4 C 0 190154 0.00 D Common Stock 190154 0 D Series E Convertible Preferred Stock 2016-10-25 4 C 0 155548 0.00 D Common Stock 155548 0 D 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 D 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"). New Leaf Venture Associates II, L.P. ("NLV Associates II") is the general partner of NLV II and New Leaf Venture Management II, L.L.C. ("NLV Management II") is the general partner of NLV Associates II. Philippe O. Chambon, Jeani Delagardelle, Ronald Hunt, Vijay Lathi and Liam Ratcliffe are the individual managers of NLV Management II (the "Individual Managers"). NLV Associates II and NLV Management II disclaim beneficial ownership of such shares, except to the extent of their pecuniary interest therein. Vijay Lathi is a director of the Issuer and, accordingly, files separate Section 16 reports. As one of five individual managers, each of the Individual Managers disclaims beneficial ownership over the shares reported herein, and in all events disclaims pecuniary interest except to the extent of his or her economic interest. /s/ Craig L. Slutzkin, attorney-in-fact, Craig L. Slutzkin, attorney-in-fact for New Leaf Venture Management II, L.L.C., the sole general partner of New Leaf Venture Associates II, L.P., the sole general partner of New Leaf Ventures II, L.P. 2016-10-25 /s/ Craig L. Slutzkin, attorney-in-fact, Craig L. Slutzkin, attorney-in-fact for New Leaf Venture Management II, L.L.C., the sole general partner of New Leaf Venture Associates II, L.P. 2016-10-25 /s/ Craig L. Slutzkin, attorney-in-fact, Craig L. Slutzkin, attorney-in-fact for New Leaf Venture Management II, L.L.C. 2016-10-25 /s/ Craig L. Slutzkin, attorney-in-fact, Craig L. Slutzkin, attorney-in-fact for Philippe O. Chambon 2016-10-25 /s/ Craig L. Slutzkin, attorney-in-fact, Craig L. Slutzkin, attorney-in-fact for Jeani Delagardelle 2016-10-25 /s/ Craig L. Slutzkin, attorney-in-fact, Craig L. Slutzkin, attorney-in-fact for Ronald M. Hunt 2016-10-25 /s/ Craig L. Slutzkin, attorney-in-fact, Craig L. Slutzkin, attorney-in-fact for Liam Ratcliffe 2016-10-25