X0306 4 2022-03-03 0 0001521036 Lantheus Holdings, Inc. LNTH 0001754976 Marshall Robert J. Jr. C/O LANTHEUS HOLDINGS, INC. 331 TREBLE COVE ROAD NORTH BILLERICA MA 01862 0 1 0 0 CFO and Treasurer Common Stock 2022-03-03 4 A 0 25911 0.00 A 152843 D Common Stock 2022-03-04 4 S 0 2570 49.983 D 150273 D Stock Option (right to buy) 49.93 2022-03-03 4 A 0 14773 0.00 A 2032-03-03 Common Stock 14773 14773 D Consists of 8,637 restricted stock units that vest in equal installments over a three-year period and 17,274 Total Shareholder Return performance-based restricted stock units ("PSUs") that cliff vest following a three-year performance period. The amount of PSUs included in this Report reflects the target award, however the ultimate award size can range from 0% to 200% of the target based on the actual performance achieved at the end of the performance period. The Company requires certain senior executives to cover tax liabilities resulting from the vesting of their equity awards pursuant to sell-to-cover transactions in compliance with Rule 10b5-1. The transaction reported in this Form 4 was effected in compliance with Rule 10b5-1 to satisfy withholding tax liabilities of the Reporting Person associated with the vesting of restricted stock previously granted and reported on a previously filed Form 4. The option vests in three equal annual installments beginning on March 3, 2023. /s/ Daniel M. Niedzwiecki, attorney-in-fact 2022-03-07