Pre-tax vs post-tax deductions
Pre-tax deductions reduce your taxable wages before tax is calculated. Post-tax deductions come out after. Some pre-tax deductions reduce FICA — others do not.
| Deduction | Reduces federal taxable wages? | Reduces FICA? | Reduces state taxable wages? |
|---|---|---|---|
| Traditional 401(k) | Yes | No | Usually yes |
| Roth 401(k) | No | No | No |
| HSA (via payroll) | Yes | Yes | Usually yes |
| FSA (Health or Dep. Care) | Yes | Yes | Usually yes |
| Health/Dental/Vision (Section 125) | Yes | Yes | Usually yes (PA: no) |
| Voluntary life insurance (post-tax) | No | No | No |
| Union dues | No | No | Some states allow at filing |
| Garnishment / child support | No | No | No |
Specific employer plans may differ. Always confirm with your benefits portal or payroll team.
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