X0306 4 2021-05-12 0001104506 INSMED Inc INSM 0001402051 Lewis William 700 US HIGHWAY 202/206 BRIDGEWATER NJ 08807 true true Chair and CEO Common Stock 2021-05-12 4 A 0 28344 A 207952 D Stock Option (right to buy) 26.46 2021-05-12 4 A 0 137280 0 A 2031-05-12 Common Stock 137280 137280 D Represents Restricted Stock Units, each representing a contingent right to receive one share of Common Stock, granted pursuant to the Company's 2019 Incentive Plan. The Restricted Stock Units vest and become available as follows: twenty five (25%) percent on each anniversary of the date of grant through the fourth anniversary date of the grant. Each Restricted Stock Unit was received as a grant on May 12, 2021, for no consideration. Stock options granted under the Company's 2019 Incentive Plan. The options become exercisable based on the following vesting schedule: twenty five percent (25%) vest on the first anniversary of the grant date and an additional twelve and one half percent (12.5%) vest on each sixth month anniversary date thereafter through the fourth anniversary of the date of grant. /s/ William Lewis, by Christine Pellizzari as Attorney in Fact 2021-05-14