Effective January 1, 2023, 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 $162,200 from $147,000 and Tier II maximum will increase to $118,800 from $109,200. 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 2023 is $162,200. There is no maximum for the compensation subject to Tier I [Med]. The Tier II rate for employees will remain at 4.9% for 2023. The maximum compensation subject to Tier II tax for 2023 is $118,800.