It’s that time of year when Americans check their finances and set goals for 2026. Two weeks ago, we made one clear recommendation: earn your full 401(k) match. What we didn’t stress enough is an equally important consideration — what kind of 401(k) are you contributing to?

That choice often gets forgotten in favor of more exciting decisions you have to make, like “What should I buy?” But for many people, the amount of control they actually have here is surprising. 

Tax time: We’ve written about rigid 401(k) plans, high expense ratio “investments”, and all the ways that retirement savings can be squandered. However, we haven’t really talked about the biggest benefit of qualified accounts — the tax part. While US income tax rates sit near historic lows, where and how you save still matters.

• Contributions to a Traditional IRA or 401(k) reduce your taxable income in the current year — the same is true for pretax FSA and HSA contributions.
• Contributions to a Roth IRA or Roth 401(k) are made after taxes, meaning you pay tax now and lock in your current tax rate.

Tax Arbitrage

That “lock-in” is where many investors slip up — your tax rate depends on where you live and how much you earn. Yet many high earners continue to shovel money into Roth accounts despite being in high tax brackets. A quick pay stub check helps explain why that choice matters:

• If you live in a high-tax locality, pretax contributions don’t just lower your federal taxable income — they also (temporarily) get you out of paying high state and local taxes.
• Every dollar you contribute to a pretax 401(k), IRA, FSA, or HSA saves you money now — and gives you greater control over when you choose to be taxed. 

Pay Now or Later?

Don’t mistake the arbitrage for ‘getting out of paying tax forever.’ You will pay eventually; the real value of qualified accounts is optionality — choosing when and where taxation occurs.

• Pre-tax accounts can be converted to post-tax Roth accounts at strategic times, such as during a lower-income year or after moving to a lower-tax state.
• A tax bill applies at conversion, but waiting until your total tax rate is lower can meaningfully reduce what you owe.

Some conditions: There are cases where high earners cannot deduct Traditional IRA contributions. However, we won’t get into the weeds here at The Average Joe and will remind you to consult a tax professional if you have pointed questions about your specific situation or how qualified accounts impact your holistic financial plan. The point of this article is simple: Qualified contributions exist primarily for one big purpose — tax savings. If you’re not getting those, you’re missing the main benefit.