Iowa Lump Sum Tax: Calculation, Exclusion, and IA 1040 Reporting

The Iowa lump sum tax is a state charge equal to 25% of the federal tax figured on federal Form 4972 for a qualifying lump-sum distribution from a retirement plan.¹ It only reaches you if the plan participant was born before January 2, 1936, because that is the federal eligibility cutoff for Form 4972.² In 2026 that leaves a narrow group: participants age 90 or older, and beneficiaries of participants who met the birth-date rule. If you were born after January 1, 1936, and you are taking your own retirement distribution, this tax does not apply to you at all.

Who Actually Owes It in 2026

Federal law lets certain older taxpayers calculate a separate tax on a large retirement payout using 10-year averaging, a 20% capital gain election, or both, on Form 4972. Iowa adds 25% of whatever federal tax that form produces.¹ Form 4972 is closed to anyone born on or after January 2, 1936.²

If you inherit a plan, the birth-date test looks at the deceased participant, not you. A 60-year-old beneficiary of a parent born in 1933 can still land inside this tax. A 60-year-old taking their own distribution cannot. The participant also needs five years in the plan before the year of distribution when taking it themselves, and Form 4972 can only be used once per participant after 1986. Beneficiaries get one use per deceased participant.²

What Counts as a Qualifying Distribution

The payout itself has to meet the federal definition. You must receive the entire balance from all of an employer’s qualified plans of one kind (pension, profit-sharing, or stock bonus) within a single tax year.³ Partial withdrawals do not qualify, and rolling any portion into another retirement account breaks the qualification.

One of four triggering events must apply:

The participant’s death, with the balance paid to a beneficiary.
The participant reaching age 59½ before the distribution.
Separation from service, available only to common-law employees.
Disability, available only to self-employed individuals.

Iowa adopts these federal triggers without modification through its reference to Section 402(e).¹

How to Calculate What You Owe

Finish federal Form 4972 first. The separate federal tax it produces, whether from 10-year averaging, the 20% capital gain election, or both, is your starting number.² Iowa’s tax is 25% of that figure.¹

If Form 4972 figures a federal tax of $8,000 on the distribution, the Iowa lump-sum tax is $2,000. It is assessed under Iowa Code 422.5(7) in addition to Iowa’s regular income tax on your other income.¹

The Exclusion That Erases the Tax for Most Recipients

Iowa Code 422.5(7)(b) exempts a lump-sum distribution from this tax entirely if the recipient meets any of the following:¹

Age 55 or older on December 31 of the tax year.
Disabled, at any age.
Surviving spouse or qualifying survivor (including sons, daughters, mothers, and fathers of the participant) where the participant would have qualified based on age or disability.
Surviving spouse of a sheriff, deputy sheriff, firefighter, police officer, or other protection-occupation worker, regardless of whether the deceased met the age or disability test.

Because the Form 4972 birth-date rule already puts every eligible participant at 90 or older, participants themselves clear the age-55 threshold automatically. The group left paying this tax is essentially beneficiaries under 55 who are not disabled and do not fit the survivor categories.⁴

Residency Rules

Residency decides whether you owe the tax at all. Full-year Iowa residents owe 25% of the entire federal Form 4972 tax. Part-year residents owe it only on a distribution received while they were an Iowa resident. Nonresidents are not subject to the Iowa lump-sum tax, even when the pension was earned during Iowa employment.⁵

How to Report It on the IA 1040

There is no separate Iowa version of Form 4972. References online to an “IA 4972” are incorrect. You complete the federal Form 4972, multiply the resulting federal tax by 25%, and enter that number on Line 6 of the IA 1040.⁵

Attach a copy of the completed federal Form 4972 to your IA 1040. E-filing software usually handles the attachment automatically; paper filers should place the federal form behind the main return.⁵ Keep the Form 1099-R from the plan administrator as well, since its distribution codes confirm the payout qualifies for Form 4972 treatment.²

Estimated Payments and Interest

A lump-sum distribution can produce a large one-time Iowa liability. If you expect to owe $1,000 or more in Iowa income tax from income not subject to Iowa withholding, Iowa requires quarterly estimated payments.⁶ A pension payout with no Iowa withholding easily crosses that line.

Underpayment is calculated on Form IA 2210 as a daily interest charge for each late day, following the federal underpayment structure.⁷ Unpaid Iowa balances also accrue interest at 10.0% annually for 2026.⁸ If you know a qualifying distribution is coming, arranging voluntary Iowa withholding with the plan administrator, or making an estimated payment in the quarter you receive the money, avoids the charge.

1
Iowa Legislature. Iowa Code 422.5 – Tax Imposed Exclusions Alternate Tax Rate
2
Internal Revenue Service. Form 4972 – Tax on Lump-Sum Distributions
3
Legal Information Institute. 26 USC 402(e)(4) – Lump-Sum Distribution
4
Iowa Department of Revenue. Retirement Income Tax Guidance
5
Iowa Department of Revenue. Iowa Lump-Sum Tax
6
Iowa Department of Revenue. Estimated Income Tax Payments
7
Iowa Department of Revenue. Penalty for Underpayment of Estimated Tax
8
Iowa Department of Revenue. Penalties and Interest Rates