When do I file for the Iowa homestead exemption on a new house?
The July 1 deadline, why a house closed this fall misses the 2026 year, and what the 2026 law change from a credit to an exemption means for a new owner.
File once, with your city or county assessor, after you own the house and live in it. Applications are due July 1 for the current assessment year, and an application that arrives after July 1 counts for the next year. If you closed on a new build or an existing house this fall, the July 1, 2026 date has passed, so the filing that matters is the one due by July 1, 2027.
Iowa's own instructions describe who qualifies. You have to be an Iowa resident who files Iowa income taxes, own the home, and occupy it. You can claim only one homestead in the state, so a family that keeps its old house while the new one is finished claims whichever one it actually lives in. The form is the Homestead Tax Exemption, number 54-028, and it goes to the assessor for the city or county where the house sits.
Once granted, the exemption carries forward without refiling for as long as you stay eligible. The Union County assessor's page adds a detail that catches new owners: you may not be able to apply online until your name shows on the assessor's record as the deed holder. On a new build bought from a builder, that can mean waiting until the sale is recorded and the record updates.
The benefit itself is new this year. The Iowa Department of Revenue says Senate File 2472, signed May 18, 2026, replaced the homestead tax credit with a homestead tax exemption. The old credit was worth the tax on $4,850 of value. The new exemption takes 10 percent off the home's taxable value, with a floor of $5,500 and a cap of $20,000. The change applies starting with assessment year 2026, which is paid in September 2027 and March 2028. The Iowa League of Cities summary adds that the $20,000 cap rises with inflation starting with the 2027 assessment year.
An illustration with round numbers: a house with $300,000 of taxable value would hit the $20,000 cap, since 10 percent would be $30,000. A house with $120,000 of taxable value would get a $12,000 exemption. A house with $40,000 of taxable value would get the $5,500 floor. Use the taxable value from your own assessment notice, since that is the figure the 10 percent applies to.
Iowa taxes run a year behind. Following the department's own example, the 2027 assessment year is the one paid in September 2028 and March 2029, so an exemption filed by July 1, 2027 first shows up on those bills. That is our reading of the schedule, so confirm the year with your assessor.
None of this changes whether building beats buying. It does belong in the comparison, because the exemption applies the same way to a new house and an existing one once you live there. The buy or build calculator on this site sets the cost to build against recorded Polk County sales so the two paths can be compared on the same terms.