The Johnston Brief
Assessed values in Polk County have been climbing for years, and a lot of Johnston homeowners never realize they can push back. Here's how your tax bill is actually built, what the city's levy is, how to check whether your assessment is fair, and exactly how to protest it - including the short window each spring when you're allowed to.
The City of Johnston's FY2026 levy is $11.4379 per $1,000 of taxable value - but that's just the city's slice. The Polk County Assessor values your home as of Jan 1; if you think it's too high, you file a written protest with the Board of Review between April 2 and April 30, backed by comparable sales. Look up your assessment at assess.co.polk.ia.us. Credits like the homestead exemption and a statewide rollback lower what you actually pay.
Your Johnston property tax isn't set by one office; it's built in four layers, from the assessor's market value down through the rollback, credits, and the combined levy rate:
The city's share of the levy is $11.4379 per $1,000 of taxable value for FY2026, unchanged from the prior year and on the higher side for the metro (Ankeny runs about $9.90, Urbandale about $9.98). But the city is only one slice; the school district is typically the biggest, and the county, DMACC and the transit authority levy the rest. Iowa property taxes are paid in arrears, in two installments (September and March).
Pull your own record on the Polk County Assessor site at assess.co.polk.ia.us. Search your address and you'll see your assessed value, the details on file for your home (square footage, year built, condition), and recent sales of comparable properties - the exact ammunition you'd need to appeal.
Online property & assessment search: assess.co.polk.ia.us → · Office: 111 Court Ave, Rm 195, Des Moines, IA 50309. New assessment notices go out in the spring in odd-numbered years (with updates in between).
File a written protest with the Polk County Board of Review between April 2 and April 30, backed by comparable sales; you can protest only during that specific window each year.
1. Pull comparable sales near you (the assessor site and your Realtor can both help; our housing dashboard is a starting point). 2. File a written protest with the Board of Review between April 2 and April 30 - in person or postmarked in that window - to the Polk County Assessor's office. 3. Attach your evidence: comparable sales, a recent independent appraisal, or documentation of condition problems. 4. Request an oral hearing on the form if you want to appear. The Board of Review meets in May and usually finishes by month's end. 5. If denied, you can appeal to the Iowa Property Assessment Appeal Board (PAAB) or district court within the deadline on the decision.
You're protesting the value, not the tax bill - argue that your assessed value is higher than your home's actual market value as of January 1. "My taxes went up" isn't grounds; "comparable homes sold for less than my assessment" is.
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The City of Johnston's property tax levy for fiscal year 2026 is $11.4379 per $1,000 of taxable value, unchanged from the prior year. That is the city's share only; your total bill also includes levies from Polk County, the Johnston Community School District, DMACC and the transit authority, so the combined rate is higher.
Only between April 2 and April 30. Miss the window and you generally wait until the next year (with narrow exceptions).
No - filing a protest with the Board of Review is free. You'd only pay if you hire an appraiser or a firm to help build your case.
If the Board of Review denies your protest, you can appeal further to the Iowa Property Assessment Appeal Board (PAAB) or to district court, within the deadline stated in the Board's decision - generally about 20 days after the Board adjourns.
You apply for the homestead exemption once and it carries forward. If you bought recently and never filed, do it through the Polk County Assessor - and check the extra exemption if you're 65 or older.
Johnston housing market · Moving to Johnston · Cost of living · Sales tax