X0306 4 2023-03-02 0 0001521036 Lantheus Holdings, Inc. LNTH 0001754976 Marshall Robert J. Jr. C/O LANTHEUS HOLDINGS, INC. 201 BURLINGTON ROAD, SOUTH BLDG BEDFORD MA 01730 0 1 0 0 CFO and Treasurer Common Stock 2023-03-02 4 A 0 20283 0.00 A 141348 D Common Stock 2023-03-03 4 A 0 17391 0.00 A 158739 D Stock Option (right to buy) 73.35 2023-03-02 4 A 0 11822 0.00 A 2033-03-02 Common Stock 11822 11822 D Consists of 6,761 restricted stock units that vest in equal installments over a three-year period and 13,522 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 transaction reported in this Form 4 reflects additional shares of common stock issued by the Company to the reporting person upon the vesting of relative Total Shareholder Return PSUs that were previously granted and included in the Form 4 filed on March 5, 2020. The number of shares reported in the Form 4 reflected 100% of the target number of shares underlying the PSUs. The number of shares that actually vested under the PSUs equaled 200% of the target number of shares. Accordingly, the number of shares reported in this Form 4 reflects the difference between the number of shares that actually vested under the PSUs and the target number of shares originally included in the Form 4. The option vests in three equal annual installments beginning on March 2, 2024. /s/ Eric M. Green, attorney-in-fact 2023-03-06