X0407 4 2023-05-03 1 0001411207 Allison Transmission Holdings Inc ALSN 0001195347 ASKREN STANLEY A C/O ALLISON TRANSMISSION HOLDINGS, INC. ONE ALLISON WAY INDIANAPOLIS IN 46222 1 0 0 0 0 Common Stock 2023-05-03 4 M 0 8536 0 A 14448 D Common Stock 2023-05-03 4 M 0 3823 0 A 18271 D Deferred Stock Units 2023-05-03 4 M 0 2880 0 D Common Stock 2880 0 D Dividend Equivalent Rights 2023-05-03 4 M 0 591 0 D Common Stock 591 0 D Deferred Stock Units 2023-05-03 4 M 0 454 0 D Common Stock 454 0 D Deferred Stock Units 2023-05-03 4 M 0 492 0 D Common Stock 492 0 D Deferred Stock Units 2023-05-03 4 M 0 596 0 D Common Stock 596 0 D Deferred Stock Units 2023-05-03 4 M 0 3600 0 D Common Stock 3600 0 D Restricted Stock Units 2023-05-03 4 M 0 3746 0 D Common Stock 3746 0 D Represents the deferred stock units ("DSUs") and related dividend equivalents payable upon the reporting person's separation from service. The reporting person did not stand for re-election at Allison Transmission Holdings, Inc.'s (the "Company") 2023 annual meeting of stockholders and his term ended on May 3, 2023. Includes 8,022 DSUs and 514 related dividend equivalents. Settlement of restricted stock units ("RSUs") and related dividend equivalents. Includes 77 dividend equivalents. Each DSU is the economic equivalent of one share of the Company's common stock. The DSUs become payable, in common stock, or at the Company's election cash, at the earlier of the reporting person's separation from service or a change in control. DSUs earn dividend equivalents when dividends are declared on the Company's common stock. On May 9, 2019, the reporting person was granted 2,880 DSUs that vested on May 6, 2020. Each dividend equivalent right is the economic equivalent of one share of the Company's common stock. The dividend equivalent rights accrued on previously awarded DSUs and were payable on May 3, 2023, the date of the reporting person's separation from service. On November 8, 2019, the reporting person was granted 454 DSUs that vested on November 8, 2019. On February 10, 2020, the reporting person was granted 492 DSUs that vested on February 10, 2020. On May 6, 2020, the reporting person was granted 596 DSUs that vested on May 6, 2020. On May 7, 2020, the reporting person was granted 3,600 DSUs that vested on May 5, 2021. Each RSU represents a contingent right to receive one share of the Company's common stock. On May 5, 2022, the reporting person was granted 3,746 RSUs that vested on May 3, 2023. /s/Eric C. Scroggins, Attorney-in-Fact 2023-05-05