There is no dollar limit on how much you can roll over from a 401(k) to a Roth IRA. You could move $20,000 or $2 million in a single transaction and the IRS will not stop you. The practical ceiling is the tax bill: every pre-tax dollar you convert becomes ordinary income in the year of the rollover, so what you can afford to owe in April is what governs the size of the move.
No Contribution Cap, No Income Limit
The annual contribution limits that apply to Roth IRAs do not apply to rollovers. For 2026, direct Roth IRA contributions are capped at $7,500, or $8,600 if you are 50 or older, and putting in more than that triggers a 6% excise tax on the excess for every year it stays in the account.1Internal Revenue Service. Retirement Topics – IRA Contribution Limits Rollovers are explicitly excluded from that cap because you are relocating existing retirement savings, not adding new money.
The IRS also exempts rollovers from the one-per-year rule that limits IRA-to-IRA transfers. A plan-to-IRA rollover falls outside that restriction entirely, so you can roll over funds from a 401(k) to a Roth IRA even if you already completed a separate IRA rollover earlier in the year.2Internal Revenue Service. Rollovers of Retirement Plan and IRA Distributions
Income phase-outs are the other rule that does not carry over. Direct Roth contributions shut off for single filers with modified AGI above $168,000 and joint filers above $252,000 in 2026, but those thresholds have no bearing on rollovers.1Internal Revenue Service. Retirement Topics – IRA Contribution Limits A household earning $500,000 can convert its entire 401(k) balance without restriction. This is the main reason high earners use 401(k)-to-Roth conversions as a planning tool: if your income locks you out of contributing directly, rolling over old 401(k) money accomplishes the same goal of getting assets into a tax-free-growth account.
What the Conversion Will Cost in Taxes
When pre-tax 401(k) money moves into a Roth IRA, the IRS treats the entire converted amount as ordinary income for that tax year.3Internal Revenue Service. Topic No. 413, Rollovers From Retirement Plans You have never paid income tax on those funds, so the government collects at conversion. The top federal rate for 2026 is 37%, which applies to taxable income above $640,600 for single filers and $768,700 for joint filers.4Internal Revenue Service. IRS Releases Tax Inflation Adjustments for Tax Year 2026
A large conversion can push you into a higher bracket. Someone with $150,000 of regular income who converts an additional $100,000 from a 401(k) would report $250,000 in total income, with the top portion of the conversion taxed at 32% or higher. Paying the tax from a separate savings or brokerage account preserves the full converted balance inside the Roth. If you use the 401(k) funds themselves to cover the bill, you reduce the amount that gets to grow tax-free, and the portion diverted to taxes can be treated as a taxable distribution subject to the 10% early withdrawal penalty if you are under 59½.
Estimated Payments
A conversion large enough to create a significant tax liability can also trigger an underpayment penalty if you do not adjust withholding or make estimated payments during the year. The safe harbor requires you to pay in at least 90% of your current-year tax or 100% of your prior-year tax, 110% if your prior-year AGI exceeded $150,000.5Internal Revenue Service. 2026 Form 1040-ES If your regular withholding does not cover the conversion income, filing a quarterly estimated payment in the same quarter as the conversion is the simplest fix.
Direct vs. Indirect Rollover
How the money physically moves matters more than most people expect. Two paths exist, and picking the wrong one can cost you thousands in unnecessary withholding.
Direct (Trustee-to-Trustee)
In a direct rollover, the 401(k) plan sends the funds straight to the Roth IRA custodian. No taxes are withheld, and you never personally handle the money. The plan may cut a check, but it will be made payable to the receiving institution “for the benefit of” you, not to you personally.2Internal Revenue Service. Rollovers of Retirement Plan and IRA Distributions This is the cleanest method and the one most institutions recommend.
Indirect (60-Day)
In an indirect rollover, the plan pays the distribution directly to you. When that happens, the administrator is required by law to withhold 20% for federal income tax before sending the check. On a $100,000 distribution, you receive $80,000 and $20,000 goes to the IRS as a prepayment.
You then have 60 days from the date of receipt to deposit the full original amount into the Roth IRA.6Office of the Law Revision Counsel. 26 USC 402 – Taxability of Beneficiary of Employees Trust That means the full $100,000, not just the $80,000 you received. To close the $20,000 gap, you need to come up with that money from another source. If you only deposit $80,000, the missing $20,000 is treated as a taxable distribution and may also be hit with a 10% early withdrawal penalty if you are under 59½.7Internal Revenue Service. Publication 575, Pension and Annuity Income You would eventually recover the withheld $20,000 as a tax credit when you file, but in the meantime you are out of pocket. The direct rollover avoids this problem entirely.
The Five-Year Clock on Converted Funds
Once money lands in your Roth IRA through a conversion, a separate clock starts. Each conversion carries its own five-year holding period, beginning on January 1 of the year the conversion takes place. If you withdraw the converted amount before five years have passed and you are under 59½, you owe a 10% penalty on the taxable portion of the conversion, even though you already paid income tax on it at the time of the rollover.8Internal Revenue Service. Publication 590-B, Distributions From Individual Retirement Arrangements
Once you reach 59½, that penalty disappears regardless of how long the conversion has been in the account.9Internal Revenue Service. Retirement Topics – Exceptions to Tax on Early Distributions So this rule is primarily a concern for people converting well before their late 50s and planning to access the money early. If you are converting at 62, it is effectively irrelevant.
Take Your RMD Before You Convert
If you have reached the age when required minimum distributions kick in, currently 73, you must take your RMD for the year before rolling over any remaining balance. The RMD itself cannot be converted. Rolling over a required minimum distribution triggers a 6% excess contribution penalty for every year the money stays in the Roth.10Internal Revenue Service. Publication 590-B, Distributions From Individual Retirement Arrangements
The sequence is: calculate the RMD, withdraw it and pay the income tax on it, then convert whatever additional amount you want. Everything above the RMD is eligible for rollover.2Internal Revenue Service. Rollovers of Retirement Plan and IRA Distributions
After-Tax 401(k) Contributions Get Special Treatment
Some 401(k) plans allow after-tax contributions beyond the standard pre-tax or Roth deferral limit. If your account holds a mix of pre-tax and after-tax money, IRS Notice 2014-54 lets you split the distribution: direct the pre-tax portion to a traditional IRA and the after-tax portion to a Roth IRA. This matters because the after-tax contributions going into the Roth have already been taxed. You only owe tax on the earnings tied to those contributions, not the principal.11Internal Revenue Service. Guidance on Allocation of After-Tax Amounts to Rollovers, Notice 2014-54
To make this work, you need to instruct the plan administrator before the distribution occurs. Using the IRS’s own example: if you have $80,000 in pre-tax funds and $20,000 in after-tax contributions, you can direct the $80,000 to a traditional IRA and the $20,000 to a Roth IRA. The entire Roth deposit is after-tax money, minimizing the immediate tax hit. Not every plan supports this kind of split distribution, so confirm availability before assuming it.
Starting the Rollover and Reporting It
To begin, you need your 401(k) plan administrator’s name and plan ID, plus the account number and transfer details for the receiving Roth IRA. Most administrators provide a distribution request form through the employer’s benefits portal or HR department. On the form you will specify the dollar amount or elect a full balance transfer and select the transfer method. Choose “direct rollover” or “trustee-to-trustee transfer” unless you have a specific reason to take an indirect distribution. Some plans charge a modest processing or wire fee for outgoing transfers.
Two forms will document the move. The 401(k) plan issues a Form 1099-R reporting the distribution, typically by the end of January following the tax year of the conversion.12Internal Revenue Service. 2025 Instructions for Forms 1099-R and 5498 The Roth IRA custodian files Form 5498 with the IRS by June 1 of the following year, reporting the rollover. Confirm that the amounts on both forms match what you actually transferred. Discrepancies are one of the fastest ways to trigger IRS correspondence, and they are almost always a paperwork error rather than a real problem, but they still need to be resolved.
Report the conversion on your federal tax return for the year the distribution occurred. The converted amount goes on Form 1040 as part of your gross income, unless you rolled over only after-tax contributions, which are not taxed again. If the 1099-R has not arrived by mid-February, contact the plan administrator directly rather than filing without it.