Most 401(k) articles stop at “contribute enough to get the match.” That’s good advice, and I’ll repeat it, but it leaves out two things people actually ask me: how the 2026 numbers fit together once you add catch-up contributions, and what happens to the account if you move out of the United States. This guide covers both, with every regulated figure tied to a page on irs.gov that you can click and check.
I’m a retired chartered accountant, and the questions I got asked most were never about investing cleverness. They were “am I using this account properly?” and “what can I get wrong?” So the guide follows that order: what the account is, how to get the most out of it, the honest downsides, and then the part most guides skip.
One thing up front: I’m a finance writer, not your CPA or financial advisor, and this is general information, not personalized financial or tax advice. KnowWiser earns nothing from anything in this article; there are no affiliate links. The figures were verified against irs.gov in October 2026, and I’ve dated the page so you can see how current it is.
What is a 401(k), and how is it different from an IRA?
A 401(k) is a retirement savings plan run by your employer, funded by automatic deductions from your paycheck, with its own contribution limits and rules. An IRA is a separate account you open yourself at a brokerage; it doesn’t depend on your job.
There are two common flavors of 401(k), and your plan may offer one or both:
- Traditional (pre-tax) 401(k). Your contributions come out of your paycheck before income tax, so your taxable income is lower today. You pay ordinary income tax when you take the money out in retirement.
- Roth 401(k) (after-tax), if your plan offers it. You get no tax break today, but qualified withdrawals later are tax-free. Not every plan has this option, so check your enrollment screen.
Payroll deferral is what makes it work. You pick a percentage; your employer sends it to the plan provider each pay period; it’s invested in whichever funds you chose from the plan’s menu. Because it happens before the money lands in your bank account, you rarely miss it. That automation is one of the 401(k)‘s underrated features.
The practical differences from an IRA: 401(k) limits are much higher (table below), the investment menu is chosen by your employer rather than by you, and your employer may add money on top. I won’t re-explain the Roth-versus-traditional decision here; our 401(k) vs Roth IRA guide covers that comparison for beginners, and this article goes deeper on getting the most from the 401(k) itself. If you want the IRA side in the same depth — traditional versus Roth, the limits, and what happens to an IRA if you leave the US — see our companion complete guide to IRAs.
How do you get the maximum benefit from your 401(k) in 2026?
In this order: capture the full employer match, raise your contribution toward the 2026 limit, keep the investments low-cost, and avoid touching the money early. Here they are one at a time.
Step 1: Are you capturing the full employer match?
The match is the single most valuable feature of most 401(k)s, so it comes first. If your employer matches part of what you contribute and you contribute less than the matched amount, you’re turning down pay.
I can’t tell you your match, because it varies by plan. Common patterns are an employer that matches dollar-for-dollar up to a percentage of your pay, or one that matches half of what you put in up to a cap. Those describe how formulas work, not what you’ll find. Your plan’s Summary Plan Description (SPD) states the exact formula; your HR portal or plan provider can send it to you.
Two other plan terms matter just as much as the formula:
- Vesting. The match may not be fully yours right away. Plans can make you wait before employer contributions become yours, either all at once after a period or in steps. If you leave before you’re vested, you can lose part of the match. The SPD spells out your schedule; I won’t quote a number because it differs by plan.
- Timing. Some plans calculate the match per pay period. If you hit the annual limit early in the year, you might miss out on the match for the rest of the year. Ask your plan administrator how yours works.
Worked example (hypothetical, not your plan). Say your salary is $100,000 and your plan matches 50% of your contributions up to 6% of pay. That’s an invented formula for illustration only.
- Contribute 3%: that’s $100,000 × 3% = $3,000 from you, plus a match of 50% × $3,000 = $1,500.
- Contribute 6%: $100,000 × 6% = $6,000 from you, plus a match of 50% × $6,000 = $3,000.
Moving from 3% to 6% adds $3,000 of your own money and brings another $1,500 of employer money with it. Every year you stay at 3%, that $1,500 is gone. If you want to see how that gap compounds over decades, our compound interest calculator lets you test it with your own numbers.
Step 2: How much can you contribute in 2026?
The IRS limit on your own (employee) 401(k) deferrals for 2026 is $24,500, up from $23,500 in 2025. If you’re 50 or older, you can add a catch-up contribution of $8,000, and there’s a higher catch-up for people turning 60 through 63. The source is the IRS’s November 2025 announcement, 401(k) limit increases to $24,500 for 2026, and its cost-of-living table of limits.
| Your situation in 2026 | Employee deferral | Catch-up | Total you can defer |
|---|---|---|---|
| Under 50 | $24,500 | none | $24,500 |
| Age 50 to 59, or 64 and older | $24,500 | $8,000 | $32,500 |
| Turn 60, 61, 62 or 63 during 2026 | $24,500 | $11,250 | $35,750 |
The totals in the last column are my arithmetic ($24,500 + $8,000 = $32,500; $24,500 + $11,250 = $35,750), not separate IRS figures. Two caveats matter here:
- The $11,250 higher catch-up applies only in the year you turn 60, 61, 62 or 63. The IRS says that for 2026 this limit “remains $11,250 instead of the $8,000.” At 64 and over you’re back to the regular age-50 catch-up.
- Catch-up contributions and the Roth option are plan features, not guarantees. Your plan has to offer them. Ask your plan administrator. I also can’t tell you how catch-up contributions are treated at higher incomes; the rules there have been changing, so confirm with your plan.
There’s a second, bigger number you may see: $72,000. That’s the Section 415(c) cap on total annual additions to your account in 2026, employee and employer money combined, before catch-up contributions. For most employees the binding limit is the $24,500 you control yourself; the $72,000 mostly matters when your employer contributes generously. Your plan administrator can tell you how your plan counts it.
You don’t have to max the account to benefit from it. Most people can’t, and the IRS limit is a ceiling, not a target. A sensible order is: get the full match, then increase your percentage whenever you get a raise, then work toward the limit if your budget allows.
Step 3: What should you invest in inside the plan?
Generally, low-cost, broadly diversified index funds are the sensible default, and the plan’s default option is worth a second look. I’m describing a direction here, not telling you how to allocate. That depends on your age, goals and comfort with risk.
Two practical points:
- Fees compound too. Every fund in your plan has an expense ratio, and it comes out of your returns every year. Index funds are typically much cheaper than actively managed funds. Your plan’s fee disclosure shows the actual figures for your funds; I won’t invent a number for your plan.
- Check what you’re in by default. Many plans put new enrollees into a default option chosen by the employer, which might be a stable-value fund, a money-market fund, or a target-date fund. Some of those are fine; some are very conservative for a 30-year-old. Open your account and look at what you actually hold, because the default isn’t always the best fit.
Returns are never guaranteed, whatever you pick.
Step 4: How do you avoid early-withdrawal penalties (and what is the Rule of 55)?
Taking money out before age 59½ generally triggers a 10% additional tax on top of regular income tax. That comes from IRS Topic no. 558, Additional tax on early distributions, and it applies to the portion of the distribution included in your gross income.
Worked example (hypothetical). You’re 45 and take a taxable $10,000 distribution. The 10% additional tax is $10,000 × 10% = $1,000. Your ordinary income tax comes on top of that, at whatever your rate is. It’s a steep price for borrowing from your own future.
The IRS lists exceptions, and one gets a lot of attention: the Rule of 55. The exact wording on Topic 558 is: “Distributions made to you after you separated from service with your employer after attainment of age 55.” Three things to know:
- It’s for employer plans only, not IRAs. If you roll the money into an IRA, you lose this exception.
- It applies to the plan of the employer you left, not to old 401(k)s from earlier jobs.
- Plans have their own rules. Many read it as separating from service in or after the calendar year you turn 55, and some plans don’t allow partial withdrawals at all. Confirm with your plan before you leave a job on the strength of it.
Other IRS exceptions include disability and a birth or adoption (up to $5,000). The full list is on Topic 558, and I’d read it before assuming any exception applies to you. Even when the 10% is waived, ordinary income tax usually still applies to pre-tax money.
What are the honest pros and cons of a 401(k)?
The 401(k) is a strong tool with real trade-offs. It isn’t magic, and any pitch that mentions only the upsides is leaving something out. Here are both sides.
Pros
- Tax deferral. Traditional contributions reduce your taxable income now, and the money grows without yearly tax on the growth. Roth contributions give you tax-free qualified withdrawals instead.
- The employer match, if your plan has one. It’s the one feature you can’t replicate in an IRA.
- High limits. $24,500 of your own money in 2026, compared with $7,500 for an IRA per the same IRS announcement.
- Automation. Money leaves your paycheck before you see it. For many people, this matters more than any investment choice.
- Creditor protection. Employer retirement plans often get significant legal protection from creditors, but there are exceptions and the details depend on the plan and your situation, so check with the plan administrator or an attorney.
Cons
- A limited investment menu. You choose from what your employer’s plan offers, which may be thin.
- Fees. Some plans carry higher costs than you’d pay on your own. Your plan’s fee disclosure tells you.
- The early-withdrawal penalty. The 10% additional tax before 59½ (above) makes the money inconvenient to reach.
- Taxable withdrawals. Pre-tax money is taxed as ordinary income when you take it out, so the balance isn’t all yours to spend.
- Required minimum distributions. Per the IRS’s RMD FAQs, you must take your first RMD for the year you reach age 73, and you may delay that first one to April 1 of the following year. The IRS also says “the RMD rules do not apply to Roth IRAs or Designated Roth accounts while the owner is alive,” so a Roth 401(k) has no lifetime RMDs. The penalty rules are in our RMD guide.
- Vesting. If your match has a vesting schedule, leaving early can cost you part of it.
If you’re thinking about moving pre-tax money into a Roth account at some point, that’s a taxable conversion with its own planning; I walk through it in how much to convert to a Roth before year-end.
What happens to your 401(k) if you leave the US?
Moving abroad doesn’t change the account itself. A 401(k) generally stays put until a distribution is triggered, and then the tax consequences depend heavily on your tax status. I’ll stay with what the IRS says and won’t guess beyond it.
I’ll say this plainly: I’m not a cross-border tax expert, and I haven’t moved a retirement account abroad. Below is what the US rules say about the account. How another country taxes it, and whether a treaty helps you, is a separate question that depends on your country, citizenship and visa or immigration status. For that, you need a cross-border tax professional.
Is leaving the US the same as leaving your job?
No. They are different events. You can keep an employer plan after you leave the country if you stay employed, and you can leave a job without leaving the country. The question “what do I do with my 401(k)?” arises when you separate from an employer; moving abroad adds a tax layer to whatever you choose.
What are your three options?
You can leave the money in the plan, roll it into an IRA, or cash it out. These options are about the account, and they’re the same whether you live in Ohio or abroad.
| Option | What it is | Main things to check |
|---|---|---|
| Leave it in the plan | Keep the account with your former employer’s plan | Plan rules on staying, fees, the investment menu, and whether the Rule of 55 matters to you |
| Roll it into an IRA | A direct (trustee-to-trustee) rollover to an IRA | No withholding on a direct rollover; you lose the Rule of 55 exception on the rolled amount |
| Cash it out | Take a distribution | Income tax, possibly the 10% additional tax before 59½, and mandatory withholding |
Leaving it in the plan is the default for many people, but ask your plan whether it keeps accounts for former employees and what that costs. Rolling it into an IRA gives you more investment choice; if you do, use a direct rollover so the money moves from one custodian to the other without passing through your hands. Per IRS Topic no. 413, mandatory withholding doesn’t apply to a direct rollover. The 20% rule below is about money paid to you from an employer plan; IRAs follow their own withholding rules.
What happens if you cash out?
If you are a US person and the check is paid to you, the plan must withhold 20% of the taxable amount for federal income tax, and you can’t opt out. That’s from the same Topic 413. The 20% is a prepayment toward your tax, not the final bill. The distribution is income, and if you’re under 59½ the 10% additional tax on early distributions can apply on top.
If the money does come to you, you have 60 days to roll it into an IRA or another plan. But there’s a catch: the withheld 20% was sent to the IRS, so to roll over the whole amount you’d need to replace it from other money. Whatever you don’t replace is treated as a taxable distribution.
Worked example (hypothetical). A $50,000 taxable cash-out paid to a US person has 20% withheld: $50,000 × 20% = $10,000 goes to the IRS and $40,000 reaches you. If you wanted to roll the full $50,000 into an IRA, you’d need $10,000 from elsewhere to make up the difference. A direct rollover would have moved all $50,000 with nothing withheld.
Does the rule change if you are a non-resident alien (foreign person)?
Yes, and the withholding can be higher. The IRS page on plan distributions to foreign persons says a plan paying a distribution to a foreign person “must generally withhold 30% of the payment for federal income tax (IRC Section 1441(a)).”
Here’s what else the IRS says, and what I’m deliberately not saying:
- The 30% can only be reduced with proper paperwork. A lower rate requires valid documentation, such as Form W-8BEN. A tax treaty between the US and your country of residence may reduce or eliminate the rate on pension income. Without a valid W-8BEN, the 30% can’t be reduced.
- The reporting is different. Distributions to foreign persons are reported to you on Form 1042-S, not the Form 1099-R that US persons receive. The IRS’s pension and annuity withholding page and Publication 515 cover the mechanics.
- I won’t give you treaty rates. Treaties differ by country and by the type of plan, and some treat private pensions more favorably than others. I’m not going to state a number here, because the wrong one could cost you real money.
- Withholding isn’t the whole picture. If you’re under 59½, the 10% additional tax from Topic 558 may also apply to a cash-out. How that interacts with the non-resident rules depends on your situation, so I’m not going to calculate it for you.
- “Foreign person” is a tax-status label, not a mailing address. Whether a plan treats you as one depends on your tax status, and that’s something to settle with your plan administrator and a cross-border professional before you request a distribution, not after.
- Reporting duties may exist. Moving abroad can create reporting obligations of its own. Confirm them with a cross-border tax professional.
What I’d do before moving, if this were my situation: find out what your plan allows for former employees and people with a foreign address; ask the plan how it would treat a distribution; get a cross-border tax professional to look at your specific country and status; and don’t cash out under time pressure. A direct rollover to an IRA is often the simpler way to keep options open, but the right answer depends on facts I don’t have.
The short version
- Match first. Contribute at least enough to capture your full employer match, and read your Summary Plan Description for the formula and vesting.
- 2026 limits. $24,500 of your own deferrals; $8,000 more at 50 and over; $11,250 instead of $8,000 in the year you turn 60 to 63, if your plan allows it.
- Don’t touch it early. A 10% additional tax generally applies before 59½. The Rule of 55 is an employer-plan-only exception, so check your plan.
- Know the trade-offs. Limited menus, fees, taxable withdrawals and RMDs at 73 (none for a Roth 401(k) while you’re alive) are the price of the tax benefits.
- If you leave the US, the account doesn’t change, but a distribution can: 20% mandatory withholding on a cash-out paid to a US person, and generally 30% for a foreign person unless a treaty and a valid Form W-8BEN reduce it. Get cross-border tax help before you move money.
See what your match and contributions could add up to
Everything above comes down to two levers: how much you put in, and how much your employer adds. Our retirement number calculator models both. Enter your current savings, salary, monthly contribution and your employer’s contribution as a percentage of pay, and it projects your balance to your retirement age and shows whether the money lasts. Run your current contribution first, then the one that would capture your full match, and compare the two. The returns you enter are assumptions, not promises, but seeing the gap in your own numbers is usually more convincing than anything I can write.
Sources
- IRS — 401(k) limit increases to $24,500 for 2026, IRA limit increases to $7,500 (2026 deferral, catch-up and higher 60–63 catch-up limits)
- IRS — COLA increases for dollar limitations on benefits and contributions (2026 limits table, including the Section 415(c) cap)
- IRS — Topic no. 558, Additional tax on early distributions from retirement plans other than IRAs (10% additional tax before 59½; Rule of 55 and other exceptions)
- IRS — Retirement plan and IRA required minimum distributions FAQs (RMD age 73; Roth accounts)
- IRS — Topic no. 413, Rollovers from retirement plans (direct rollover, 20% mandatory withholding, 60-day rule)
- IRS — Plan distributions to foreign persons require withholding (30% withholding, IRC Section 1441(a), Form W-8BEN, Form 1042-S)
- IRS — Pensions and annuity withholding and Publication 515 (withholding on payments to foreign persons)
Verified as of October 2026 against irs.gov: the 2026 deferral limit ($24,500), the age-50 catch-up ($8,000), the age 60–63 catch-up ($11,250), the $72,000 Section 415(c) cap, the 10% early-distribution additional tax and Rule of 55 wording (Topic 558), the RMD age and Roth exemption, the 20% mandatory withholding and direct-rollover rules (Topic 413), and the 30% withholding rule for foreign persons. Match formulas, vesting, fees, plan features and treaty treatment are not quantified because they vary by plan and by country. Worked examples use invented round numbers and are not predictions. Tax rules change and every situation differs; confirm your own numbers on irs.gov, with your plan administrator, or with a tax professional (a cross-border one if you are leaving the US) before you act.