The tax-advantaged retirement accounts are the single biggest legal advantage in U.S. personal finance. Here is how the Roth IRA and 401(k) actually work, what makes each worth maxing, and the order to fill them.
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The Roth IRA lets you contribute $7,000/year [VERIFY irs.gov] of already-taxed money that then grows and gets withdrawn tax-free forever. The 401(k) lets you contribute $23,500/year [VERIFY] of pre-tax income that grows tax-deferred and gets taxed on withdrawal. Employer match on the 401(k) is free money. Roth IRA wins on early-career flexibility. Most people should use both: capture the 401(k) match first, max the Roth IRA, then return to max the 401(k).
You contribute money you have already paid income tax on. The account grows tax-free. You withdraw tax-free in retirement. Contributions (but not earnings) can come out at any time without penalty. That flexibility makes it the single most powerful account for early-career savers.
The annual contribution limit is $7,000 for 2026 [VERIFY irs.gov], with a $1,000 catch-up for savers aged 50 and older. Contributions can be made up until the tax filing deadline (mid-April) for the prior year. Open the account at Fidelity, Schwab, or Vanguard (no account fees, no commissions on index funds). Invest the contribution in a total-market fund (VTI, FSKAX, FZROX) or a target-date fund. Do not leave the cash sitting in the settlement fund.
The Roth IRA has an income phase-out. Above roughly $165K single or $246K married filing jointly [VERIFY 2026 irs.gov], direct contributions are reduced or disallowed. Above those limits, use the Backdoor Roth instead.
The 401(k) is an employer-sponsored plan with a much higher contribution limit: $23,500 for 2026 [VERIFY irs.gov], plus a $7,500 catch-up at age 50 and another larger catch-up around age 60 under SECURE 2.0 [VERIFY]. Contributions come directly from payroll before income tax is calculated, so a $10,000 contribution reduces this year's taxable income by $10,000.
Most employers match a portion of contributions. Typical matches are 50 percent of the first 6 percent of salary, or 100 percent of the first 3 percent. The match is the highest-return investment in personal finance: a dollar that doubles on contact. Capture the full match before doing almost anything else.
Many plans now offer a Roth 401(k) option, which has the same $23,500 limit but uses after-tax dollars for tax-free growth (same mechanics as Roth IRA, higher limit, no income restriction). Self-employed individuals can open a Solo 401(k) with the same limit plus an employer-side contribution on top.
The rule of thumb: choose Roth when your current tax rate is lower than your expected retirement tax rate; choose Traditional when your current rate is higher. In practice, that means early-career and moderate-income savers typically favor Roth, while high earners in peak years often prefer Traditional for the immediate deduction.
If you are enrolled in a High-Deductible Health Plan (HDHP), the Health Savings Account sits alongside the Roth and 401(k) as a core retirement vehicle, not merely a medical account. HSA contributions are pre-tax (like Traditional 401(k)), growth is tax-free (like Roth IRA), and withdrawals for qualified medical expenses are tax-free at any age. After age 65, non-medical withdrawals work like a Traditional IRA (income tax, no penalty).
The 2026 HSA contribution limit is $4,400 single / $8,750 family [VERIFY irs.gov], with a $1,000 catch-up at 55. Invest the balance in index funds inside the HSA custodian (Fidelity's HSA has no fees and supports the same mutual funds as their brokerage). Full mechanics in HSA Deep Dive.
Tax-advantaged space is use-it-or-lose-it on an annual basis. If you do not contribute this year, the room is gone. Assuming foundation is in place (emergency fund, high-interest debt cleared):
Instant 50 to 100 percent return on the matched portion. Nothing beats this.
Triple tax advantage. Only account in the code that offers this. Only possible with HDHP enrollment.
Flexibility, no RMDs, estate-planning advantages, plus tax-free growth on the full amount.
Pre-tax compounding powerhouse. Return and fill the remaining 401(k) room.
If your 401(k) offers after-tax contributions with in-service rollover, you can push tens of thousands more into Roth space annually. Details in Backdoor Roth.
Last updated 2026-04-14. Not financial advice. Do your own research.