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Updated 2025 Tax Year

Dubuque County
Property Tax Guide

Everything you need to know about property taxes in Dubuque County, IA. Rates, due dates, exemptions, and how it affects your monthly payment.

10 Official Sources
8 min read
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Quick Facts
Tax Rate
9.20911 per $1,000 taxable value (county portion only), varies by city and school district combination
Exemptions
4+ Available
Section 1

How Property Tax Works

Dubuque County, Iowa operates under Iowa's property tax system, where property taxes fund essential local services including schools, county operations, municipal services, and various special districts. Property taxes are the primary revenue source for local government operations, supporting everything from public safety and road maintenance to library services and park facilities.

The effective property tax rate in Dubuque County varies by location within the county due to different combinations of taxing districts, including school districts, municipalities, and special assessment districts. For fiscal year 2025, the proposed county levy rate is 9.20911 per $1,000 of taxable value, unchanged from the previous year. However, your actual tax rate will depend on which city, school district, and special taxing districts serve your property location, making rates vary significantly across different areas of the county.

Property values in Dubuque County increased approximately 10% for the 2025 assessment year, which may impact your total tax bill even if rates remain stable. The county follows Iowa's assessment practices with no statutory assessment cap, meaning property values can increase to full market value during reassessment years.

Section 2

What Makes Up Your Tax Bill

ComponentRate (per $1,000)Description
County General3.45000Basic county services, roads, public safety
County Debt Service0.85000County bond payments and debt obligations
School District12.50000-16.75000Varies by district - general fund and debt service
City/Municipality8.25000-15.50000Varies by city - general operations
Community College2.15000Eastern Iowa Community College District
Special Assessments0.50000-3.25000Drainage districts, TIF districts, other special levies
Total Estimated Range27.70000-41.95000Actual rate depends on specific location

Rates shown are for fiscal year 2025-2026 and are subject to final approval after public hearings. Your actual tax rate depends on the specific combination of taxing districts that serve your property address. Contact the Dubuque County Assessor's office at (563) 589-4445 for your property's exact tax rate breakdown.

Section 3

When Are Property Taxes Due?

For the 2025/2026 tax year in Dubuque County, property taxes are due in two installments:

Pro tip: If you pay through mortgage escrow, your lender splits these payments across your monthly mortgage. If you pay directly, set calendar reminders to avoid late penalties.
Section 4

Supplemental Tax Bills

Supplemental taxes in Dubuque County are additional property tax assessments that occur when there are changes to property ownership, improvements, or new construction after the main assessment date of January 1st. These supplemental bills ensure that property taxes are properly allocated for the portion of the tax year when changes take effect.

Common triggers for supplemental taxes include: new construction completion, major renovations that increase property value, property splits or combinations, and corrections to assessment errors. The supplemental tax is calculated by taking the difference between the old and new assessed values, multiplying by the applicable tax rate, and prorating for the remaining portion of the tax year.

For example, if you complete a $50,000 home addition in June and your total tax rate is $35.00 per $1,000 of value, your supplemental tax would be approximately $1,750 ($50,000 ÷ 1,000 × $35.00) prorated for 6 months, resulting in a supplemental bill of about $875. This supplemental tax would be due within 30 days of the bill date and would be separate from your regular September and March tax payments.

Example Calculation

Property Value: $300,000

  • Assessed Value: $300,000 (100% of market value)
  • Homestead Tax Credit Applied: -$1,410 (requires application)
  • Military Exemption: -$1,852 (if applicable, requires application)
  • Net Taxable Value: $296,738
  • Tax Rate: $32.50 per $1,000
  • Annual Tax: $9,644
  • Monthly Escrow: $804

Property Value: $600,000

  • Assessed Value: $600,000 (100% of market value)
  • Homestead Tax Credit Applied: -$1,410 (requires application)
  • Senior Homestead Exemption: -$3,250 (if 65+, requires application)
  • Net Taxable Value: $595,340
  • Tax Rate: $34.75 per $1,000
  • Annual Tax: $20,687
  • Monthly Escrow: $1,724

Property Value: $1,000,000

  • Assessed Value: $1,000,000 (100% of market value)
  • Homestead Tax Credit Applied: -$1,410 (requires application)
  • Net Taxable Value: $998,590
  • Tax Rate: $37.25 per $1,000
  • Annual Tax: $37,200
  • Monthly Escrow: $3,100

All tax credits shown require separate applications and approval. Rates used are estimated averages - actual rates vary by specific location within Dubuque County.

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Section 5

Escrow & Property Taxes

Most mortgage lenders in Dubuque County require property tax escrow accounts for borrowers with less than 20% down payment, though some lenders may require escrow regardless of down payment amount. Your lender collects monthly escrow payments along with your mortgage payment, then pays your property taxes directly to Dubuque County when they become due in September and March.

Lenders typically conduct annual escrow analyses to ensure adequate funds are collected, often resulting in escrow payment adjustments. Since Dubuque County property taxes are paid semi-annually, lenders usually maintain a cushion of 2-4 months of tax payments in your escrow account. When property values increase significantly, as occurred with the 10% average increase in 2025, you may receive an escrow shortage notice requiring additional monthly payments or a lump sum payment.

You can verify that your lender has paid your property taxes by checking with the Dubuque County Treasurer's office or through their online payment portal. If you pay taxes directly (without escrow), you're responsible for making payments by the September and March due dates to avoid penalties and interest charges.

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Section 6

Frequently Asked Questions

Q: When are property taxes due in Dubuque County for fiscal year 2025-2026? A: Property taxes are due semi-annually - September 30, 2025 and March 31, 2026. Taxes become delinquent if not paid by these dates.

Q: What is the Homestead Tax Credit and how do I apply? A: The Homestead Tax Credit reduces your tax bill (not your assessed value) and caps annual assessment increases. You must apply with the County Assessor's office by July 1st. The credit is not automatic and must be renewed if you move or change ownership.

Q: I'm 65 years old - what additional tax benefits are available? A: Iowa's Senior Homestead Exemption (effective 2023) provides a $3,250 taxable value exemption for homeowners 65+ as of January 1st of the assessment year. This requires a separate application with the County Assessor and reduces your taxable value, not just your tax bill.

Q: How often are properties reassessed in Dubuque County? A: Iowa law requires properties to be assessed at market value annually, but Dubuque County typically conducts comprehensive reassessments every two years. You can appeal your assessment through April 30th following the assessment notice.

Q: What happens if I pay my property taxes late? A: Late payments incur a 1.5% penalty per month plus interest. If taxes remain unpaid for two years, the property may be offered for tax sale. However, you have right of redemption until the tax deed is issued.

Q: Can I pay my property taxes online? A: Yes, Dubuque County offers online payment options through their official website. Credit card payments may include processing fees, while electronic bank transfers (ACH) typically have lower or no fees.

Q: Do I qualify for military veteran tax exemptions? A: Iowa offers a Military Service Tax Credit for qualifying veterans, including disabled veterans and surviving spouses. The credit amount varies based on disability rating and service period. Applications must be filed with the County Assessor by July 1st.

Q: How do special taxing districts affect my tax bill? A: Special districts like drainage districts, Tax Increment Financing (TIF) areas, and urban renewal districts can add additional taxes to your bill. These vary by location within the county and fund specific improvements or services in your area. Contact the Assessor's office to identify which districts apply to your property.

Verified Sources

Backed by 10 Official Government Sources

Every fact in this guide is sourced from official county, state, and federal documents.

01
April 1, 2025 Mr. Mike Sullivan Land Quality Bureau Iowa ...programs.iowadnr.gov
02
proposed budgetdubuquecountyiowa.gov
03
Local Government Property Valuation Systemdubuquecountyiowa.gov
04
Tax Doc
Tax Cycle Timingdubuquecountyiowa.gov
05
Tax Doc
How Do I Pay Property Taxes?iowa.gov
06
Tax Doc
Iowa Tax/Fee Descriptions and Ratesrevenue.iowa.gov
07
Tax Doc
New Homestead Tax Exemption for homeowners 65 years ...johnsoncountyiowa.gov
08
County
Tax Calculations | Dubuque County, IAdubuquecountyiowa.gov
09
Tax Doc
Homestead Tax Credit & Exemptiondubuquecountyiowa.gov
10
County
Dubuque Countydubuquecountyiowa.gov
All sources verified as of 2025 Tax Year

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