Effective January 1, 2025, the maximum amounts of compensation subject to Railroad Retirement Tier I and Tier II taxes will increase to the following:  Tier I maximum will increase to $176,100 from $168,600 and Tier II maximum will increase to $130,800 from $125,100.  The Tier I tax consists of two components, a Social Security equivalent (Tier I [SS] 6.20%) component and a Medicare (Tier I [Med] 1.45%) component.  The maximum compensation subject to Tier I [SS] tax for 2025 is $176,100.  There is no maximum for the compensation subject to Tier I [Med].  The Tier II rate for employees will remain at 4.9% for 2025 (13.1% for employers). The maximum compensation subject to Tier II tax for 2025 is $130,800.