The outcome depends on several things: whether the money is traditional, Roth, or after-tax; whether your plan allows a distribution; how much you convert; your current and future tax picture; and how the transfer is completed.
This guide covers eligibility checks, the transfer steps, timing and tax factors, alternatives, and common mistakes. It is general education, so confirm current IRS and plan rules before acting.
Key Takeaways
- A traditional 401(k)-to-Roth-IRA move is a conversion that generally adds ordinary income.
- Confirm your plan allows a distribution, and ask how pre-tax, Roth, and after-tax money will be handled.
- Direct rollovers are easier to control than indirect ones.
- Partial, staged conversions can help manage brackets and cash flow.
How to Convert a 401(k) to a Roth IRA
Step 1: Confirm the 401(k) type and eligibility
Review your latest statement and summary plan description. Identify:
- Traditional pre-tax balances
- Designated Roth balances
- After-tax balances
- Employer contributions
- Any outstanding loans
Then ask the plan administrator whether you have a distributable event. Per the IRS guidance, a 401(k) may permit distributions after leaving the employer, at age 59½ while employed, or for hardship, depending on plan terms and contribution source. Don't assume an active employee can move the whole account.
Loans matter too. An unpaid loan can be offset against the account, and that offset counts as an actual distribution.
Step 2: Open or verify the receiving Roth IRA
Open a Roth IRA if you don't have one. Confirm the account registration, beneficiary designation, and the custodian's instructions for incoming rollovers.
Income limits trip people up. The 2026 Roth contribution phase-outs ($153,000 to $168,000 for single filers; $242,000 to $252,000 for joint filers) apply to regular contributions.
They don't apply to rolling over an eligible workplace-plan balance, and the $7,500 annual IRA limit doesn't cap rollovers either.
Step 3: Estimate the tax and choose the amount
The taxable portion lands in your gross income for the year of conversion. To estimate it, gather expected wages, investment income, deductions, filing status, and state of residence.
Useful 2026 reference points:
- Standard deduction: $32,200 married filing jointly, $16,100 single, $24,150 head of household
- The 22% bracket begins at taxable income of $50,400 (single) or $100,800 (joint)
- The 24% bracket begins at $105,700 (single) or $211,400 (joint)
Compare a full conversion with converting in slices over several years. Plan to pay the tax from non-retirement cash so you don't drain emergency reserves. State rules vary, so check your state revenue department.
Large conversions can also trigger estimated-tax obligations. You generally need estimated-tax payments when you expect to owe at least $1,000, and the prior-year safe harbor rises to 110% when prior-year AGI exceeds $150,000.
Step 4: Request, complete, and document the transfer
Prefer a direct rollover. The plan pays the Roth IRA custodian directly, and the mandatory 20% withholding doesn't apply. Confirm exactly how checks should be payable and where wires should go.
An indirect rollover is riskier:
- The plan withholds 20% from the check paid to you.
- You have 60 days to deposit the money.
- To roll over the full gross amount, you must replace the withheld 20% from other funds.
- Miss the deadline and the IRS may offer a waiver, but don't count on it.
Afterward, confirm the money arrived in the correct Roth IRA and choose investments deliberately.
Expect Form 1099-R. Code G generally marks a direct rollover of non-Roth plan money to a Roth IRA, while code H marks a designated Roth rollover. Report the rollover on Form 1040 lines 5a and 5b, and keep every statement for your records.
When Should You Convert a 401(k) to a Roth IRA, and What Do You Need First?
A conversion isn't automatically a win. You are trading a tax bill now for potential tax-free qualified withdrawals later.
When a conversion may be worth considering
- A lower-income year, such as the gap between a job and retirement income
- Same or higher expected tax rates in retirement, as Fidelity's guidance notes
- A long retirement horizon
- A goal of leaving tax-efficient assets to heirs
It may fit poorly if you:
- Need the money within five years
- Lack cash to pay the conversion tax
- Already sit in a high bracket
- Expect a much lower rate later
What to gather before starting
- Current 401(k) statements with balances by source
- Plan distribution rules and loan status
- Beneficiary details
- Recent tax returns, expected income, and filing status
- State tax information
- Cash available to pay the tax
Ideally, the plan administrator, Roth IRA custodian, tax professional, and financial planner work from the same numbers. Zebulon Tax & Wealth Advisory takes a tax-first, integrated approach to Roth conversion planning and withdrawal strategy, and can be a resource for complex situations. Zebulon doesn't prepare tax returns or give legal advice, so pair it with a CPA or attorney as needed.
Key Parameters, Common Mistakes, and Troubleshooting
The amount, source, timing, and how you pay the tax all shape the result.
Conversion amount and bracket capacity
Converted money stacks on top of your other income. Converting only up to the top of your current bracket is a common way to limit the tax impact.
A big conversion can also ripple outward:
- Medicare IRMAA: 2026 premiums use 2024 income. Surcharges begin at $109,000 (individual) or $218,000 (joint) of MAGI.
- Social Security: more benefits may become taxable. Up to 85% can be taxed once combined income passes $34,000 single or $44,000 joint.
- ACA credits and FAFSA: taxable conversion income flows into AGI and can affect both.
Account source, basis, and destination
Pre-tax, designated Roth, and after-tax money are treated differently. Under IRS Notice 2014-54, pre-tax and after-tax amounts in one distribution can be sent to different destinations, such as pre-tax to a traditional IRA and basis to a Roth IRA. Ask the administrator for the source breakdown.
The destination must be a Roth IRA if you want Roth treatment. A Roth 401(k)-to-Roth-IRA rollover is a different transaction from converting traditional money, and qualified designated-Roth distributions are generally excluded from income.
Timing and holding periods
The calendar year of completion determines which return carries the income. Required minimum distributions can't be converted, so take any RMD first. The first-RMD age is generally 73, rising to 75 for people born in 1960 or later.
Each conversion has its own five-year clock. Under age 59½, withdrawing converted taxable amounts within that period may trigger the 10% additional tax. Keep separate records for every conversion, because conversions after 2017 can't be undone.
Paying the tax
Paying from outside cash keeps more invested in the Roth IRA. Withholding from the distribution shrinks what lands in the account, and if you're under 59½, withheld amounts that aren't rolled over may face the 10% additional tax. Model the payment against cash reserves, charitable giving, and other planning rather than treating the conversion in isolation.
Common mistakes
- Assuming every 401(k) can be moved while you're still working
- Rolling to a traditional IRA and expecting Roth treatment
- Ignoring pre-tax, Roth, and after-tax differences
- Missing the 60-day deadline or mishandling withholding
- Failing to verify the deposit or report the conversion using Form 1099-R
Troubleshooting
If the administrator says the transfer isn't available, confirm the plan's separation-from-service and in-service rules. Then compare keeping the plan, a traditional rollover IRA, a new employer plan, or waiting.
If money is deposited incorrectly, a form is missing, or the transaction is coded oddly, contact the plan administrator and custodian promptly. Save all statements and correspondence, and talk to a tax professional before correcting anything.
Alternatives to Converting a 401(k) Directly to a Roth IRA
The right choice depends on whether you want to preserve tax deferral, simplify investments, keep plan features, or get Roth treatment.
Traditional rollover IRA or new employer plan
Rolling pre-tax money to a traditional IRA or a new employer's plan preserves tax deferral and avoids conversion income. Compare these factors before you move:
- Fees and ongoing costs
- Investment menu and flexibility
- Creditor protection rules
The Department of Labor notes ERISA plan assets are shielded from employer creditors, while IRA protection depends on bankruptcy law and varies by state outside bankruptcy.
Keep the 401(k) or use an in-plan Roth option
Staying put can preserve institutional investment options. Some plans also allow in-plan Roth conversions with no move to an IRA, though the taxable amount still counts as income. Availability varies: Vanguard's data shows 36% of plans offered it in 2025, and only 4% of eligible participants used it. Confirm your plan's terms.
Stage the decision or take a different distribution
Spreading conversions over several years can keep each one inside a chosen bracket. Cashing out is a separate decision. The distribution is generally taxable and may add the 10% additional tax before 59½ (with an exception for separation from service in or after the year you turn 55). It also ends tax-deferred growth.
Conclusion
Conversion works best when the account is eligible, the taxable amount and its funding are planned, and the transfer is documented correctly. The biggest risks come from poor preparation, confusing a rollover with a conversion, and overlooking source and timing rules.
Weigh today's taxes against future tax-free income, RMD exposure, cash flow, and legacy goals. Because a Roth conversion is irrevocable, verify current IRS and plan rules and get personalized tax guidance first.
Frequently Asked Questions
How much tax will I pay if I convert my 401(k) to a Roth IRA?
It depends on the taxable portion converted, your other income, filing status, deductions, and state rules. Run a current-year projection rather than relying on a universal estimate.
Can I move my 401(k) into a Roth IRA without penalty?
A direct rollover is not an early distribution, so the 10% additional tax generally doesn't apply. Cash withdrawals, age, timing, and account type change that.
Can I convert my traditional 401(k) to a Roth IRA?
Often yes, after a distributable event or if your plan allows an in-service transfer. The pre-tax amount converted is generally taxable income.
Can a 401(k) be converted to a Roth 401(k)?
If your plan offers an in-plan Roth conversion, yes. Eligibility and tax treatment are plan-specific, so confirm with the administrator.
Is it a good idea to convert a 401(k) to a Roth IRA?
It can be, if future tax-free withdrawals, RMD flexibility, or legacy goals outweigh today's tax cost. Liquidity and Medicare or Social Security effects matter too.
Can an inherited 401(k) be rolled over to a Roth IRA?
A nonspouse beneficiary can't roll an inherited 401(k) into their own Roth IRA, only into an inherited IRA. Spouses have more options, so get specialized guidance first.
