THG 2018 Annual Report

The estimated amortization to be recognized in net periodic benefit cost in 2019 is de minimis. Assumptions Employers are required to measure the funded status of their plans as of the date of their year-end statement of financial position. As such, the Company has utilized a measurement date of December 31, 2018 and 2017, to determine its postretirement benefit obligations, consistent with the date of its Consolidated Balance Sheets. Weighted average discount rate assumptions used to determine postretirement benefit obligations and periodic postretirement costs are as follows: YEARS ENDED DECEMBER 31 2018 2017 Postretirement benefit obligations discount rate 4.38% 3.75% 3.75% 4.13% The following table provides the assumed health care cost trend rates used for 2018 and 2017. A one-percentage point change in these assumptions would be de minimis. DECEMBER 31 2018 2017 Health care cost trend rate assumed for next year 6.50% 6.50% med to decline (ultimate trend rate) 4.50% 4.50% Year the rate reaches the ultimate trend rate 2024 2024 112 THE HANOVER INSURANCE GROUP | 2018 ANNUAL REPORT