What to Do with Your 401(k) When You Leave a Job

When you leave a job, your 401(k) doesn't follow you. It stays at the old employer, sitting in whatever investments it was holding the day you walked out, waiting for you to do something with it.

You have four options. Most people get this decision wrong because the people they ask about it have a financial interest in a particular answer.

Here's the honest version.

The Four Options

1. Leave it at the old employer's plan.

2. Roll it into the new employer's plan.

3. Roll it into an IRA.

4. Cash it out.

Almost every advisor you talk to will recommend option 3 — the IRA rollover. That's not a coincidence. Once the money is in an IRA, it becomes an account the advisor can be paid on. The old 401(k) was outside their reach. The new IRA isn't.

That conflict doesn't automatically mean an IRA rollover is the wrong move. It often is the right move. But it means you should run the numbers yourself before assuming the recommendation you got was disinterested.

Walk through each option.

Option 1: Leave It at the Old Employer

When it makes sense.

If the old plan has good investment options at institutional-class share prices (often 0.02%–0.10% expense ratios, well below what's available in retail accounts) and a reasonable fee structure, leaving the money where it is can be the most cost-effective move. You're not losing investment flexibility — you're trading retail flexibility for institutional pricing that isn't available outside the plan.

Leaving the money also keeps it inside the ERISA umbrella, which provides strong creditor protection in federal bankruptcy proceedings. IRAs have weaker protection that varies state-by-state. For business owners and high-earning professionals with any liability exposure, this matters more than people realize.

And — important for high earners — keeping pre-tax dollars inside a 401(k) instead of an IRA preserves your ability to do clean backdoor Roth conversions. The pro-rata rule on IRA conversions counts every pre-tax IRA dollar you have when calculating the tax on the conversion. 401(k) dollars don't get counted. That's worth a lot if you're planning regular backdoor Roth contributions.

When it doesn't.

If the old plan has high fees, a thin investment menu, or fund choices you can't justify, the institutional-pricing argument falls apart. Some employers also actively encourage former employees to roll out by adding small administrative fees or restrictions.

Bottom line: if the plan is good, leaving it is the simplest answer no one will tell you to take.

Option 2: Roll It Into the New Employer's Plan

When it makes sense.

If you're moving to a new job and the new 401(k) has good investment options and a clean fee structure, consolidating into one plan simplifies your life and preserves the same ERISA and backdoor Roth advantages as Option 1.

It also keeps loan eligibility intact (if the new plan allows them), and keeps the money inside the rule-of-55 window. If you separate from this new employer between age 55 and 59½, you can take 401(k) withdrawals without the 10% early-withdrawal penalty. IRAs don't have this provision. Most people don't think about it in their 30s and 40s. It can matter quite a bit later.

When it doesn't.

Check the new plan's investment menu and total fees before rolling. Some 401(k)s are excellent. Some are terrible. The labels don't tell you which.

Bottom line: if the new plan is good, consolidating is clean and usually low-friction.

Option 3: Roll It Into an IRA

When it makes sense.

If both the old and new plans have weak investment options or high fees, an IRA gives you maximum flexibility — any fund, any ETF, any allocation. If you've moved into self-employment, an IRA also opens the door to additional retirement vehicles (Solo 401(k), SEP, SIMPLE) that work alongside it.

For people who want concentrated positions, niche asset classes, or specific tax strategies that 401(k) menus don't support, an IRA is the right structure.

When it doesn't.

Five things that get glossed over when an advisor recommends an IRA rollover:

1. Cost. The whole reason the advisor is excited about the rollover is that they get paid on the IRA. Make sure the all-in cost of the new account (advisor fee + fund expenses) is justified by what you're actually getting in return.

2. Creditor protection. You're trading ERISA protection for state-dependent IRA protection. For most W-2 employees this isn't a big deal. For physicians, business owners, and people with any liability exposure, it can be a meaningful downgrade.

3. The backdoor Roth issue. Once you have pre-tax money in any IRA, the pro-rata rule applies to future Roth conversions. If you've been doing backdoor Roths annually, an IRA rollover can complicate or eliminate that strategy. There are workarounds (rolling the IRA back into a new 401(k), for example), but most advisors won't bring this up before the rollover happens.

4. The rule-of-55 loss. You're giving up the ability to take penalty-free withdrawals between 55 and 59½ if you separate from the employer holding the 401(k). That window is worth more than most people realize when they're choosing where to put the money.

5. The NUA question. If your 401(k) holds employer stock with significant appreciation, you may qualify for Net Unrealized Appreciation treatment — paying ordinary income tax on the cost basis at distribution and long-term capital gains on the appreciation later. Rolling to an IRA forfeits this option permanently. NUA isn't right for everyone. It should be evaluated, not skipped.

Bottom line: sometimes the right answer, often the easy answer for the advisor, occasionally the wrong answer that quietly costs the client years of optionality.

Option 4: Cash It Out

When it makes sense.

Almost never.

Cashing out triggers ordinary income tax on the full distribution plus a 10% early-withdrawal penalty if you're under 59½ (some exceptions apply — separation after 55 from the plan you're cashing out, certain disability cases, hardship withdrawals with their own rules). A typical six-figure 401(k) loses 35%–45% of its value to taxes and penalties before you ever see a dollar.

If you're in serious financial hardship and need access to those funds, there are better options — a loan from the new employer's 401(k), a hardship withdrawal, or rolling to an IRA and taking a more measured distribution. None are ideal. All are better than a full cash-out.

The Questions to Ask If Someone Recommends an IRA Rollover

If an advisor recommends rolling your 401(k) into an IRA they'll manage, ask these four questions before you sign:

1. What's the all-in cost of the IRA — advisor fee plus weighted fund expenses — compared to leaving the money in the old 401(k)?

2. Does this rollover affect my ability to do backdoor Roth contributions?

3. Am I giving up any unique features by moving the money — NUA treatment, rule-of-55, creditor protection?

4. What specifically am I getting in the IRA that I can't get by leaving the money where it is?

The answers should be specific. If they're not, that's information.

The Framework

The decision rule that holds up across most situations:

• If the old plan is good, leaving it there is often the right move.

• If the new plan is good, consolidating into it is usually clean.

• If both plans are weak and you're willing to pay attention to costs, an IRA can be the right structure.

• Cashing out is almost never the right move.

That's the same framework I'd use for a friend or a client. It's also the framework most advisors won't walk you through, because three of the four answers don't generate a new fee.

If you've just left a job and you're sitting on a 401(k) decision, the most expensive thing you can do is take the first recommendation you hear without running the numbers on the alternatives. The right answer depends on the specific plans involved, your tax position, and your long-term plan. But the starting point isn't "roll it to an IRA." The starting point is the framework above.