X0609 4 2026-09-25 0000944695 HANOVER INSURANCE GROUP, INC. THG 0001584240 Egan Cynthia false C/O THE HANOVER INSURANCE GROUP, INC. 440 LINCOLN STREET WORCESTER MA 01653 true false false false false Common Stock 2026-09-25 4 A false 3.7 0 A 10209.467 D Grant of restricted stock units ("RSUs") under the Issuer's 2022 Long-Term Incentive Plan ("2022 LTIP") in connection with the accrual of dividend equivalent rights associated with RSUs previously granted under the Issuer's 2022 LTIP. Such units vest on the earlier of the one-year anniversary of the date of grant of the original underlying RSUs or the date of the next annual meeting. The Reporting Person has elected to defer such grant upon vesting pursuant to a deferral agreement. Does not include 977 shares held indirectly in a Rabbi Trust pursuant to deferral agreements. /s/ Lindsay L. Katz pursuant to Confirming Statement 2026-09-28