Under FICA Class "A," your Social Security tax and your pension contributions are both deducted from your gross salary.

Under FICA Class "C," your pension contributions are reduced by the amount of your Social Security tax.

Under FICA Class "E," only your pension contributions are deducted from your gross salary; no Social Security tax is withheld.

Tier I and II members have the option of electing Class "A" or Class "C"; Tier III, IV, and VI members are automatically assigned to Class "A." (Please note that Class "E" is no longer offered.)