How to Apply Excess Roth IRA Contribution to Next Year

To apply an excess Roth IRA contribution to next year, leave the money in the account and contribute less next year by the exact amount of the excess, so the carried-forward dollars fill part of that year’s contribution limit. This fix keeps the money in the Roth, but you owe a 6% excise tax on the excess for every year it sits unabsorbed, and you track the absorption on IRS Form 5329.¹

What the Carryforward Costs

Federal law imposes a 6% excise tax on any excess Roth IRA contribution left in your account at the end of the tax year. The tax is calculated on the lesser of the excess amount or the total value of your Roth IRA on December 31.¹ A $2,000 excess costs $120 each year until it is resolved.

The penalty repeats annually until the excess is gone. With the carryforward, you accept at least one year of that 6% charge in exchange for keeping the money (and any earnings on it) inside the Roth. For a small excess in an account that is growing, the tax shelter on the earnings can outweigh the one-time hit.

When You Can Absorb the Excess Next Year

You can apply the excess toward a later year as long as your total contributions for that year, including the carried-forward amount, stay under the annual limit.² Three conditions have to line up in the absorption year:

You have taxable compensation (wages, salary, self-employment income, or similar earnings). Without earned income, you have no contribution room at all.²
Your modified adjusted gross income is low enough to allow at least some Roth IRA contribution under that year’s phase-out ranges.
Your new Roth deposits for the year are small enough to leave room for the carryforward. If you already put in the full annual limit in new money, there is nothing left to absorb.

If you file jointly and have no earned income yourself, your spouse’s compensation can support the contribution under the spousal IRA rules, provided combined contributions do not exceed the taxable compensation on the joint return.³

For 2026, the combined Traditional and Roth IRA limit is $7,500, or $8,600 if you are 50 or older.⁴ If your income pushes you above the Roth phase-out ceiling next year, no contribution room exists, the 6% penalty continues, and you would have to wait for a qualifying year or switch to a different correction method.

Reporting the Carryforward on Form 5329

Form 5329 is where you report the excess, calculate the 6% penalty, and track absorption. Roth IRA excess contributions are handled in Part IV.⁵ The key lines:

Line 18: the total excess from the prior year, pulled from line 24 of last year’s Form 5329.
Line 19: your unused contribution room for the current year (the maximum you could have contributed minus what you actually did). This is the line that absorbs the carryforward.
Line 20: any distributions taken from the Roth during the year.
Line 21: lines 19 and 20 added together.
Line 22: line 18 minus line 21, which is whatever prior-year excess still remains. Zero or less means the carryforward is fully resolved.
Line 23: any new excess contributions made for the current year.
Line 24: lines 22 and 23 added, giving your total remaining excess.
Line 25: line 24 multiplied by 6%, or 6% of the December 31 account value if that is smaller. This is the excise tax owed.⁶

A worked example. You over-contributed $2,000 in 2025 and put in $5,000 of new money for 2026, when your limit is $7,500. On your 2026 Form 5329, line 18 shows $2,000, line 19 shows $2,500 of unused room, and line 22 drops to zero because the room fully absorbs the excess. Line 25 is zero, so no further penalty is due. You still owe the 6% penalty for 2025 on that year’s Form 5329, because the excess sat in the account through December 31, 2025.

Filing Form 5329

Form 5329 is filed as an attachment to your Form 1040 for the tax year.⁶ Most tax software handles it automatically. If you already filed your return before catching the excess, you can send a signed paper Form 5329 by itself to the address in the form’s instructions; a standalone Form 5329 cannot be filed electronically.

If the excess is from a year whose return has already been filed, submit Form 5329 with Form 1040-X (the amended return) for the year the excess first occurred, and pay the excise tax with the filing to limit interest and late-payment charges.⁶ The excise tax from line 25 flows to Schedule 2 of your Form 1040.⁵

Adjusting Next Year’s Contributions

Every dollar carried forward fills the same space as a new dollar contributed. If your 2026 limit is $7,500 and you are carrying forward $3,000 from 2025, you can only deposit $4,500 in new money for 2026.² Go one dollar over and you have created a new excess and started a fresh round of the 6% penalty.

The annual limit applies to your Traditional and Roth IRAs combined, not per account.³ Any Traditional IRA contributions you make in the absorption year further reduce the space available for the Roth carryforward. Check any automatic contributions with your custodian and turn the amount down so the total for the year stays under the reduced ceiling.

When the Carryforward Is the Wrong Fix

If you are still before your tax filing deadline for the year the excess occurred, two other options avoid the 6% penalty entirely. Withdrawing the excess plus any earnings it generated, or recharacterizing it as a Traditional IRA contribution through a trustee-to-trustee transfer, both eliminate the excise tax if completed by the due date of your return, including extensions.³² Earnings withdrawn are taxable for the year of the contribution and may trigger a 10% early distribution penalty if you are under 59½. For a 2025 excess, the standard deadline is April 15, 2026, extended to October 15, 2026 if you filed for an extension.⁷

The carryforward also becomes a poor deal when the excess is large relative to the annual limit. An excess bigger than a full year’s contribution takes more than one year to absorb, and the 6% penalty runs every year until it is gone. In that situation, withdrawing the excess after the deadline can be cheaper overall, because it stops the annual penalty immediately even though it does not undo the tax for years already elapsed.

For a modest excess, one you can absorb in a single year where you are eligible to contribute, the carryforward is the simplest correction. You pay one year of the 6% tax, reduce next year’s contribution by the excess amount, file Form 5329 to close it out on line 22, and the earnings on that money stay sheltered inside the Roth.

1
Office of the Law Revision Counsel. 26 USC 4973 – Tax on Excess Contributions to Certain Tax-Favored Accounts and Annuities
2
Internal Revenue Service. Publication 590-A (2025), Contributions to Individual Retirement Arrangements (IRAs)
3
Internal Revenue Service. Retirement Topics – IRA Contribution Limits
4
Internal Revenue Service. 401(k) Limit Increases to $24,500 for 2026, IRA Limit Increases to $7,500
5
Internal Revenue Service. Form 5329 (2025) – Additional Taxes on Qualified Plans (Including IRAs) and Other Tax-Favored Accounts
6
Internal Revenue Service. 2025 Instructions for Form 5329 – Additional Taxes on Qualified Plans (Including IRAs) and Other Tax-Favored Accounts
7
Internal Revenue Service. Get an Extension to File Your Tax Return