INSMED Inc

Rule 10b5-1 Trading Plans

Our policy governing transactions in our securities by our directors, officers and employees permits our directors, officers and employees to enter into trading plans complying with Rule 10b5-1 under the Exchange Act. The following table describes the written plans for the sale of our securities adopted, modified orterminated by our officers and directors (each as defined in Rule 16a-1(f) of the Exchange Act) during the first quarter of 2026, each of which was entered into during an open trading window and is intended to satisfy the affirmative defense conditions of Rule 10b5-1(c) (each, a Trading Plan).

(1) A Trading Plan may expire on an earlier date if all contemplated transactions are completed before such Trading Plan’s expiration date, upon termination by broker or the holder of the Trading Plan, or as otherwise provided in the Trading Plan.

In addition, during the period covered by this Quarterly Report on Form 10-Q, each of our officers entered into grant agreements relating to RSUs and PSUs that included “sell-to-cover” arrangements constituting “non-Rule 10b5-1 trading arrangements” (as defined in Item 408 of Regulation S-K), requiring the pre-arranged sale of shares upon vesting to satisfy tax withholding obligations arising solely from such vesting of the RSUs and the PSUs and the related issuance of shares. The amount of shares to be sold to satisfy the tax withholding obligations under these arrangements is dependent on the trading price of the Company’s common stock at the time of the vesting of the RSUs and the PSUs. The duration of each of these arrangements is until the final vesting date of the applicable RSUs or PSUs or the earlier forfeiture of unvested RSUs or PSUs as set forth in the applicable grant agreement.