Pre-Tax Deductions: How 401(k), HSA, and FSA Increase Your Take-Home Pay
Pre-tax deductions reduce your taxable income before taxes are calculated. Every $1,000 in pre-tax deductions saves you $120 to $370 in federal tax depending on your bracket, plus additional state tax savings. On a $100K salary, maxing your 401(k) at $23,500 saves $5,170 in federal tax alone.
Without 401(k)
$79,180
With 401(k)
$79,180
Federal Tax Saved
$0
Effective Cost
$0
401(k) Contributions (2026)
| Category | 2026 Limit |
|---|---|
| Under 50 | $23,500 |
| Age 50+ | $31,000 |
| Age 60 to 63 (super catch-up) | $34,750 |
Traditional 401(k) contributions reduce your taxable income dollar-for-dollar. If you contribute $10,000 and you are in the 22% bracket, your federal tax drops by $2,200. Your state tax also decreases if your state taxes income (e.g., California, New York).
Roth 401(k) comparison: Roth contributions are made with after-tax dollars, so they do not reduce your current tax bill. However, withdrawals in retirement are tax-free. Roth is generally better if you expect to be in a higher bracket in retirement. Traditional is better if you expect a lower bracket.
Employer match: If your employer matches 5%, that is an additional 5% of your salary contributed on your behalf, tax-free until withdrawal. Always contribute at least enough to get the full match; it is a 100% return on your money.
Health Savings Account (HSA): The Triple Tax Advantage
Tax-Free Going In
Contributions reduce taxable income
Tax-Free Growth
Investment gains are not taxed
Tax-Free Withdrawal
For qualified medical expenses
2026 limits: $4,400 (individual) / $8,750 (family). Requires enrollment in a High Deductible Health Plan (HDHP) with minimum deductible of $1,700 (individual) / $3,400 (family).
The HSA is the only account type with a triple tax benefit. After age 65, you can withdraw for any purpose without penalty (though non-medical withdrawals are taxed as ordinary income, similar to a traditional IRA).
Flexible Spending Account (FSA)
Healthcare FSA limit: $3,200 (2026). Dependent Care FSA limit: $5,000. Both reduce taxable income.
Use-it-or-lose-it: Unlike an HSA, unused FSA funds generally expire at year-end. Your employer may offer a $640 carryover option or a 2.5-month grace period, but not both. Only contribute what you are confident you will spend.
401(k) vs. HSA vs. FSA vs. Roth 401(k)
| Feature | Traditional 401(k) | Roth 401(k) | HSA | FSA |
|---|---|---|---|---|
| Tax going in | Deductible | After-tax | Deductible | Deductible |
| Tax on growth | Deferred | Tax-free | Tax-free | N/A |
| Tax on withdrawal | Taxed as income | Tax-free | Tax-free (medical) | Tax-free (medical) |
| 2026 limit | $23,500 | $23,500 | $4,400 | $3,200 |
| Unused funds | Roll over | Roll over | Roll over | Use or lose |
Optimization Priority Order for a $100K Earner
401(k) up to employer match
If your employer matches 5%, contribute at least $5,000. Free money plus tax savings.
~$1,100 tax saved + $5,000 match
Max HSA ($4,400)
Triple tax advantage makes this the most efficient savings vehicle if you have an HDHP.
~$968 tax saved
Max 401(k) ($23,500)
Fill the remaining 401(k) space for maximum pre-tax savings.
~$4,070 additional tax saved
Roth IRA ($7,000)
After-tax contributions with tax-free growth and withdrawals. Income limits apply.
No immediate tax savings, but tax-free in retirement