Railroad employees have five possible entries in Box 14 of Form W-2:

1. RRTA Compensation
2. Tier I 
3. Tier II 
4. Medicare Tax
5. Additional Medicare Tax

If you’re a railroad employee covered by the Railroad Retirement Act (RRTA), these amounts are located in Box 14 with the above descriptions

Enter the correct amounts for the above descriptions on Form W-2 in the section for employees covered by the Railroad Retirement Tax Act (RRTA).

Boxes 3, 4, 5, 6, and 7 of Form W-2 are for employees covered under the Federal Insurance Contributions Act (FICA) and should be left blank for railroad employees.