Roth vs. traditional 401(k): what hits your paycheck each week
A cash-flow-first comparison of elective deferrals: how traditional pre-tax deferrals change taxable wages versus designated Roth contributions—and what to verify about employer match.
Same deferral, different paystub story (illustrative)
Ignores state taxes and other deductions; use your stub as ground truth.
| Election | Typical paycheck effect |
|---|---|
| $500 traditional deferral | Reduces federal taxable wages by $500 for that period (within limits) |
| $500 Roth deferral | Does not reduce federal taxable wages by that amount—net pay often lower |
| Employer match | Often pre-tax—separate from your Roth vs. traditional choice |
Definitions that matter on the stub
Pre-tax elective deferrals reduce wages reported for federal income tax withholding in many plans. Designated Roth contributions are included in wages for income tax withholding purposes even though they are deferred for retirement.
FICA treatment can differ by contribution type and plan design—confirm with your employer’s SPD.
Why this is not investment advice
We are describing paycheck mechanics and tax timing concepts. Choosing Roth vs. traditional for your goals is a broader financial planning question.
What to do next
Practical next steps based on this topic.
Change elections in small steps and verify two consecutive stubs after each change.
- Compare limits: Track IRS 401(k) limits and catch-up if age-eligible.