Union County, IA Property Tax: $2,108/yr (2026)
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The effective property tax rate in Union County is 1.79% of assessed home value. On a home at the county median value of $117,800, that works out to about $2,109 per year, or $176 per month. Union County is located in southern Iowa, and is home to approximately 12,038 residents.
About Union County
Union County covers approximately 423.6 square miles in Iowa. The county is home to about 12,038 residents living in roughly 5,790 housing units, of which 63.0% are owner-occupied. The median household income is $56,813, and the median home was built in 1961.
Union County borders Adair County, Adams County, Clarke County, Decatur County, Madison County — useful comparisons if you're considering nearby areas with potentially different tax rates.
How Property Taxes Work in Iowa
Property taxes in Iowa are administered at the county level. Each county sets a millage rate applied to the assessed value of real property — the effective rate above accounts for any partial assessments and exemptions already built into the local tax base. Assessed value can differ meaningfully from current market value depending on how often the county reassesses and what fraction of market value it uses.
Most counties in Iowa offer exemptions that reduce the taxable assessed value: homestead exemptions for primary residences, senior exemptions, disability exemptions, and veteran exemptions are common. These reduce your effective rate below the county-wide average shown here. Contact the Union County Assessor's office to learn which exemptions apply to your property and when to file.
Union County vs. Neighboring Counties
| Location | Eff. Rate | Median Home | Annual Tax |
|---|---|---|---|
| Union County, IA | 1.79% | $117,800 | $2,109 |
| Iowa state average | 1.34% | — | $1,579* |
| Adair County | 1.32% | $140,600 | $1,858 |
| Adams County | 1.27% | $116,900 | $1,479 |
| Clarke County | 1.46% | $160,200 | $2,335 |
| Decatur County | 1.69% | $109,500 | $1,856 |
| Madison County | 1.55% | $236,900 | $3,681 |
| US national average | 1.10% | $281,900 | $3,101 |
*State average annual tax computed at Union County's median home value of $117,800. Source: US Census ACS 2023 5-year estimates.
Frequently Asked Questions
How does Union County's property tax rate compare to the rest of Iowa?
At 1.79%, Union County is higher than the Iowa state average of 1.34%. On a home at the county median of $117,800, that means about $2,109 per year — versus $1,579 at the state average rate, a difference of $530 per year. Compared to the national average of 1.10%, Union County is above average.
What's a typical annual property tax bill in Union County?
For a home at the county median value of $117,800, the annual property tax in Union County is approximately $2,109 — or about $176 per month. For a home worth $176,700, expect around $3,163 per year. For a $235,600 home, approximately $4,217 per year. Use the calculator above to estimate taxes for any assessed value.
Where do I appeal a Union County property tax assessment?
Property assessment appeals in Union County are handled by the Union County Assessor's office. Most jurisdictions require filing within 30–90 days of receiving your assessment notice — confirm the specific deadline with the assessor's office before submitting, as deadlines and procedures vary by county. A successful appeal can reduce your assessed value and lower your tax bill for the current and future tax years.
What exemptions are available in Union County?
Iowa counties commonly offer homestead exemptions for owner-occupied primary residences, senior citizen exemptions for qualifying homeowners aged 65 and older, exemptions for disabled residents, and veterans' exemptions. Each exemption reduces your assessed taxable value, which in turn reduces your effective tax rate below the county-wide 1.79% shown here. Contact the Union County Assessor's office to confirm which exemptions are available and the application deadlines.
Data sources: US Census Bureau ACS 2023 5-Year Estimates, US Census Gazetteer (2024), County Adjacency File