Post-tax deductions are taken from your paycheck after federal, state, and FICA taxes have already been calculated. They reduce your take-home pay but not your taxable income — unlike pre-tax deductions.
Common Post-Tax Deductions
| Deduction | Tax Status | Key Benefit |
|---|---|---|
| Roth 401(k) contributions | Post-tax | Tax-free withdrawals in retirement |
| Roth IRA contributions (via payroll) | Post-tax | Tax-free growth + withdrawals |
| Wage garnishments (court-ordered) | Post-tax | Legally mandated |
| Union dues | Post-tax | Union membership benefits |
| Life insurance (employee-paid, >$50k coverage) | Post-tax | Coverage above IRS exclusion limit |
| Charitable contributions via payroll | Post-tax | Convenience; deductible if you itemize |
Roth 401k vs Traditional 401k: The Tax Tradeoff
Traditional 401k (pre-tax): Reduces taxes now. You pay taxes when you withdraw in retirement. Better if you expect to be in a lower tax bracket in retirement.
Roth 401k (post-tax): No tax savings now. Withdrawals in retirement are completely tax-free. Better if you expect to be in the same or higher bracket in retirement, or if you're early in your career and in a low bracket now.
In 2026, the contribution limit for Roth 401(k) is the same as traditional: $23,500 ($31,000 if age 50+), or split between the two — but the combined total cannot exceed the limit.
Wage Garnishments: CCPA Limits
Federal law (Consumer Credit Protection Act) limits how much can be garnished from disposable earnings per pay period:
- Ordinary debts (credit cards, medical bills): the lesser of 25% of disposable earnings or the amount by which disposable earnings exceed 30× the federal minimum wage ($7.25 × 30 = $217.50/week)
- Child support/alimony: up to 50%–65% depending on whether the employee supports another family and how far behind they are
- Federal student loans: up to 15%
- Federal tax levies: the IRS table determines the exempt amount
How Post-Tax Deductions Show on Your Pay Stub
On a properly formatted pay stub, post-tax deductions appear after the tax section — below federal income tax, state income tax, and FICA. The order is typically: Gross Pay → Pre-tax deductions → Taxable wages → Taxes withheld → Post-tax deductions → Net Pay.