45-011: IA 2210 Schedule AI Annualized Income Installment Method 45-011 (2025)
Iowa · Iowa DOR · Used for tax years 2025
The 2025 IA 2210 Schedule AI calculates Iowa estimated tax installments using the annualized income installment method. It uses income, tax, and credits for specified periods of the year to determine required installment amounts for IA 2210.
Who files this form
The annualized income installment method is optional. You may be able to reduce or eliminate one or more required installments if your income varied during 2025, such as income from a seasonal business.
If you choose this method, you must complete both IA 2210 and IA 2210 Schedule AI and include them with your return. If you use Schedule AI for any payment due date, you must use it for all payment due dates.
What you'll need
To complete the schedule, have:
- Your 2025 IA 1040, including taxable income from line 4, exemption credits from line 8, and the credits listed on Schedule AI lines 8 and 9.
- Form IA 2210. Schedule AI line 15 uses 25% of IA 2210, line 8.
- Your income, losses, adjustments to income, Iowa lump-sum tax, and applicable credits for each period shown on the schedule.
The instructions also require a worksheet or tax form showing the calculations for each credit claimed on “line 18.” That is the line reference printed in the instructions, although Schedule AI lists credits on lines 7 through 9.
How to file
To use this method:
- Complete IA 2210 and IA 2210 Schedule AI.
- Check the box on IA 1040, line 35, indicating that you used the annualized income installment method, even if the calculated penalty is zero.
- Include both forms with your return.
The instructions repeatedly direct you to transfer each column's Schedule AI line 19 amount to IA 2210, line 16. However, the schedule itself says to transfer it to IA 2210, line 18. The supplied text contains this conflicting line reference.
The text does not provide a mailing address or e-filing directions.
Common mistakes
- Using Schedule AI for only some payment due dates. If you use it for one payment due date, you must use it for all payment due dates.
- Working across columns too soon. Complete lines 13 through 19 of one column before moving to the next column.
- Annualizing credits on lines 8 and 9. Do not annualize the credits themselves. Do annualize any income or deduction used to calculate those credits.
- Skipping the checkbox because the penalty is zero. Check the annualized-method box on IA 1040, line 35, even if the calculated penalty is zero.
- Leaving out the supporting forms. Include both IA 2210 and Schedule AI with your return.
Questions people ask
What periods does the 2025 schedule cover?
The four columns cover January 1 through March 31, January 1 through May 31, January 1 through August 31, and January 1 through December 31, 2025.
How do I calculate income for each period?
Compute Iowa taxable income for the months shown in that column. Include all gross income or loss for the period, minus adjustments to income for that period. Multiply line 1 by the line 2 annualization amount: 4, 2.4, 1.5, or 1, respectively.
What tax rate do I use on line 4?
Use the 2025 IA 1040 tax rate of 3.8% (.038) to calculate tax on the annualized income on line 3.
How does the schedule choose the required installment?
It selects the smaller of the annualized income installment or the regular installment, with the regular installment increased by amounts saved through annualizing earlier installments.
Where can nonresidents and part-year residents find more guidance?
The instructions direct nonresidents, part-year residents, and people claiming an Out-of-state Tax Credit to the IA 1040 expanded instructions at revenue.iowa.gov.