The three streams of 401(k) money
Employee contribution: what you defer from your paycheck — capped at $23,500 in 2026, +$7,500 catch-up for 50+.
Employer match: free money on your contributions — often 50% or 100% up to some percentage of salary.
Investment growth: tax-deferred compounding inside the account — historically averaging 7% real for diversified equity portfolios.
All three matter, but the employer match is by far the highest-leverage dollar. Skipping the match leaves a 50–100% instant return on the table.
Traditional vs Roth — the real decision framework
Traditional: contribution is pre-tax (lowers taxable income now); withdrawal is taxed as ordinary income later.
Roth: contribution is after-tax (no deduction); withdrawal is tax-free in retirement.
Simple rule: traditional if your marginal rate is HIGHER today than you expect in retirement. Roth if your marginal rate is LOWER today.
Most early-career professionals (lower bracket now, expected higher bracket later) should default to Roth. Most peak-earnings professionals (high bracket now, expecting retirement to be lower) should default to traditional.
Splitting 50/50 is a reasonable hedge if you're unsure.
Why 401(k) fees matter so much
A 1% annual fee compounded over 30 years can reduce your final balance by 25–30%. That's decades of savings lost to friction.
Look up the fund expense ratios in your plan. Anything above 0.5% is questionable; above 1% is bad. Target index funds typically run 0.03–0.10%.
If your plan has bad options: contribute to the match, then max IRA, then return to the 401(k) for any remaining capacity.
The optimal 401(k) priority order
1. Contribute enough to get the FULL employer match. Always first.
2. Pay off high-interest debt (credit cards, personal loans).
3. Build emergency fund (3–6 months expenses).
4. Max your IRA ($7k Roth or traditional).
5. Return to 401(k) and increase contributions toward the $23,500 limit.
6. After that: HSA, 529, taxable brokerage.
Tweak based on tax situation and goals, but this is the right default for most US workers.
Common 401(k) mistakes
- Not contributing enough to get the full employer match.
- Picking high-fee actively managed funds over index funds.
- Cashing out 401(k) when changing jobs.
- Forgetting old 401(k)s at previous employers.
- Taking 401(k) loans without weighing the job-loss risk.