Ozaukee County, home to Port Washington and roughly 92k Wisconsinites, uses Wisconsin's mill-rate-and-credits system: every taxing jurisdiction (county, municipality, school district, technical college, state) sets its own mill rate per $1,000 of assessed value, and these are combined into a single net rate applied to your property's assessed value. Wisconsin has no universal property-value homestead exemption — instead, four credits reduce what you actually owe, three of which appear automatically on your bill.
How the bill is built
Wisconsin's tax math is conceptually simple but procedurally distinctive. Your assessed value is set by the local municipal assessor (not the county) and should approximate fair market value, though the WI Department of Revenue publishes annual assessment ratios to track drift. Multiply assessed value by the combined net mill rate (sum of county + municipality + school district + technical college + state, expressed per $1,000 of value, divided by 1,000) to get your gross tax. Then subtract the credits.
Three credits apply automatically, with no application required: the Lottery and Gaming Credit (typically $200, primary residence only, funded by state lottery proceeds), the First Dollar Credit (typically $75, applies to any parcel with at least one improvement), and the School Levy Tax Credit (already embedded in the published "net" mill rate). The fourth credit — the Homestead Credit — is claimed on your Wisconsin state income tax return rather than applied to your property tax bill, and is income-limited.
2026 Ozaukee County rate breakdown (mill rate per $1,000 of assessed value, Port Washington district)
| Taxing entity | Rate |
|---|---|
| Mequon-Thiensville School District | 9.2500 |
| Ozaukee County General | 2.8500 |
| City of Mequon | 4.1500 |
| Milwaukee Area Technical College | 0.9200 |
| Combined total | 17.1700 |
As of April 29, 2026 · From Ozaukee County (municipal-level assessing).
Credits and relief for 2026
Wisconsin's approach to property tax relief is fundamentally different from every other state we cover. Instead of subtracting a homestead exemption from assessed value before applying the rate (like Florida or Texas) or applying an assessment ratio (like Tennessee or Arizona), Wisconsin keeps the full tax liability and applies four credits — three on the bill itself and one on your state income tax return.
Three automatic bill credits
Wisconsin homeowners do not need to apply for these — they appear on your tax bill automatically:
Lottery and Gaming Credit: Funded by Wisconsin lottery proceeds, this credit applies only to your primary residence (declared on the property tax bill itself; you can self-certify if it isn't already applied). The credit varies by school district and assessed value, but typical Wisconsin homeowners receive around $200 per year. If your home is your primary residence and the credit isn't on your bill, contact your municipal treasurer to add it — there's no annual reapplication.
First Dollar Credit: Applies automatically to every parcel with at least one improvement (i.e., not vacant land). Typical credit is around $75. This credit was added in 2008 to provide modest universal relief regardless of income.
School Levy Tax Credit: The state distributes funds to municipalities to offset school taxes, and this credit is already embedded in the "net" mill rate shown on your bill. You don't see it as a separate line — it's been subtracted from the gross school levy before the rate was published.
Income-tax-side: Homestead Credit
The Wisconsin Homestead Credit is a refundable credit claimed on Schedule H or H-EZ filed with your Wisconsin income tax return — NOT applied to your property tax bill. Maximum credit for the 2025 tax year is $1,168.
Eligibility (2025 cycle): you must be a Wisconsin resident all year, age 18+, with household income under $24,680. You must also meet ONE of these: age 62+, totally disabled, or have positive earned income during the year. The credit is calculated based on the relationship between household income and property taxes paid, with a maximum of $1,460 in property taxes considered.
A 2025 trap to know about: if you claim Wisconsin's retirement income subtraction on your state return, you cannot also claim the Homestead Credit. Many retirees end up choosing the larger of the two.
Veterans & Surviving Spouses Property Tax Credit
Veterans with a 100% service-connected permanent and total disability — or veterans rated individually unemployable, or unmarried surviving spouses of qualifying veterans — receive a full refund of property taxes paid on their primary Wisconsin residence (up to one acre). This is the most generous veteran property-tax benefit in any of the eight states this almanac covers. File via the Wisconsin Department of Veterans Affairs.
Appealing your assessment
Wisconsin's appeal process runs through three stages. Open Book is an informal assessor-review session typically held in May; bring comparable sales data or an independent appraisal and you can often resolve issues without filing a formal objection. The Board of Review meets in June; you must file a written notice of objection at least 48 hours before the meeting OR appear in person to preserve your right to challenge the assessment. After Board of Review, appeals go to the Wisconsin Department of Revenue (under Section 70.85) or directly to circuit court (under Section 74.37).
Most successful appeals resolve at the Open Book stage. The single most useful piece of evidence is comparable sales data for genuinely similar properties — same neighborhood, similar size, similar condition, sold in the past 12 months. The Ozaukee County (municipal-level assessing) can typically tell you which sales the assessor used to set your value.
One Wisconsin-specific quirk: even within a single municipality, the assessor's overall ratio of assessed-to-market value drifts over time. If the citywide ratio is, say, 92%, the assessor is technically required to assess you at 92% of true market value. If your assessment is at or above true market value while the citywide ratio is below 100%, you have a strong over-assessment case independent of comparable sales.