Washtenaw County, Michigan property tax appeal guide for 2027

What deadline matters first

For the 2027 tax year, Washtenaw County assessment appeals are handled by the local city or township March Board of Review, not by one countywide hearing board. The regular 2027 review season is modeled from March 8, 2027 through April 5, 2027, because Michigan law sets March Board of Review timing around the second Monday in March and completion by the first Monday in April. The State Tax Commission's assessing guide explains the March Board of Review role in Michigan's assessment process (Michigan State Tax Commission guide).

Your exact filing deadline may be earlier than April 5, 2027. Each city or township can set its own hearing schedule, appointment rules, and written-protest rules. For example, published local notices in Washtenaw-area municipalities often require a petition or appointment by a stated local deadline, so your own assessment notice and assessor's instructions matter.

For most residential and agricultural homeowners, a valuation dispute generally must go first to the March Board of Review before the Michigan Tax Tribunal will review it. Commercial, industrial, and developmental real property can have different Michigan Tax Tribunal rules and may be able to file directly by the applicable statutory deadline, so those owners should confirm the state deadline before relying on the March local dates.

A countywide planning estimate for Washtenaw County's effective property tax rate is 1.56%. That is only a planning number. Actual taxes depend on your city or township millage, school district, special assessments, and whether a change affects Taxable Value (Washtenaw County tax-rate estimate).

The common value appeal

The most common homeowner issue is Valuation / Assessed Value / True Cash Value. Use this when your assessment suggests the property was worth more than the market supports as of December 31, 2026, the valuation date for the 2027 assessment year.

Michigan's true-cash-value statute focuses on the usual selling price of the property, not a forced-sale or auction price (Michigan Legislature, MCL 211.27). In normal homeowner terms, you are trying to show what a willing buyer would likely have paid for your home around the valuation date.

Michigan assessments are intended to equal 50% of estimated true cash value. That means a home with a $400,000 true cash value would generally have an Assessed Value of about $200,000 before other rules are considered. Taxable Value is different. It is the Proposal A value used for tax billing and may be lower because of capped-value rules (Michigan Treasury FAQ).

A value appeal is strongest when the evidence tells a simple story: similar homes sold for less than the value implied by your assessment. The board is not deciding whether taxes are frustrating or whether your bill went up too much. It is deciding whether the assessment is supported under Michigan assessment standards.

One historical Ann Arbor sample shows why evidence matters. An AnnArbor.com analysis reported that, from 2007 through 2011, residents had a success rate of about 43% in city residential assessment appeals, with 1,828 granted out of 4,219 residential appeals. That is a city-specific historical sample, not a promise for any Washtenaw County homeowner in 2027 (AnnArbor.com archive).

Other reasons you might appeal

Taxable Value / Capped Value / Transfer of Ownership means the calculation of Taxable Value may be wrong. This can involve the capped-value formula, additions or losses, or whether a transfer of ownership should have uncapped the Taxable Value. This is different from arguing that market value is too high.

Property Classification means the property may be in the wrong statutory category for its actual use. Local Boards of Review hear classification issues, and Michigan has additional State Tax Commission review deadlines for some classification disputes. Keep the official classification language from your notice when you prepare your materials.

Exemption / Exemption Denial means an exemption was denied, removed, or not reflected correctly. This can include poverty exemption matters and certain personal-property exemption issues when the local Board of Review has authority. Some exemptions have separate forms and deadlines, so check the exact notice language.

Qualified Error / Clerical Error / Mutual Mistake of Fact means the record contains a factual or clerical problem, such as a wrong building characteristic, omitted correction, or other mistake that Michigan law allows a Board of Review to correct. Superior Township describes July and December Board of Review meetings as correction meetings for omissions, errors, or mistakes on the tax roll (Superior Township Board of Review).

Uniformity / Equalization means your property may be assessed at a different level than similarly situated properties without a supported reason. This is not just a comparable-sales value argument. It is an argument that similar properties in the same assessment unit are not being treated consistently.

Local Washtenaw-area materials reflect that Boards of Review may hear issues involving values, classification, transfer of ownership, and exemptions (Lima Township Board of Review). Your petition should match the official issue you are raising, because different issues need different evidence.

If your Notice of Assessment says something else changed

A Notice of Assessment is the assessment notice that tells you what the assessor put on the property for the tax year. It usually shows Assessed Value, Taxable Value, classification, exemption status, and sometimes information about transfers, additions, or losses.

If your Notice of Assessment shows a higher Assessed Value, ask whether the true cash value is too high. If it shows a higher Taxable Value, ask whether the capped-value calculation, transfer-of-ownership treatment, or additions and losses are correct.

If the notice says an exemption was denied or removed, do not treat that as a normal value dispute. Gather the exemption application, denial notice, income or eligibility documents if relevant, and any local instructions for that exemption.

If the notice shows a property detail that is simply wrong, such as the wrong building size, basement, garage, condition, or property use, preserve that as a factual correction issue. Photos, sketches, permits, inspection reports, and the assessor's record card can help the board see the mistake.

What evidence helps

For comparable sales, use closed, verifiable transfers of similar real property in the same or a competing Washtenaw County market area. Michigan's true-cash-value standard looks to the usual selling price, so forced-sale, auction, related-party, foreclosure, corrective-deed, government-compelled, partial-interest, or distress transactions usually need to be excluded or carefully explained (Michigan Legislature, MCL 211.27).

A conservative homeowner packet should use the best three to five arm's-length sales. Prefer the same neighborhood or market area, similar property type, similar age and condition, similar size, and similar site utility. If possible, keep sales near the December 31, 2026 valuation date.

Michigan mass appraisal commonly uses a 24-month sales-study period ending March 31 before the assessment year. For the 2027 assessment, the modeled mass-appraisal study period is April 1, 2024 through March 31, 2026. Sales closer to December 31, 2026 may still be useful if you document and explain them clearly. Detroit's assessor describes the 24-month study period used in Michigan assessment work, which is useful background even though Washtenaw's local study details may differ (Detroit Office of the Assessor sales-study explanation).

There is no Washtenaw County-wide hard rule in the supplied policy for a maximum radius, gross-living-area difference, lot-size difference, or required number of comparable sales. As a practical screen, try to stay within roughly 20% of gross living area and close to the same market area when the property is typical.

Rural, acreage, waterfront, agricultural, and unusual homes may require a wider search. If you use a more distant or less similar sale, explain why it is still one of the best indicators available.

Include the sale date, sale price, address or parcel number, property characteristics, and source documents. Add photos, MLS sheets, public-record pages, appraisal pages, repair estimates, or contractor letters when they help explain condition or differences.

What the board can and cannot decide

The local March Board of Review can review assessment issues that Michigan law and local procedures allow it to hear. That can include valuation, certain classification matters, exemptions, transfer-related Taxable Value questions, and corrections when properly raised.

The board cannot change millage rates, school taxes, special assessments, or local budgets. It also cannot reduce your bill simply because the bill is difficult to afford. If affordability is the issue, ask the local assessor about any poverty exemption or other exemption process that may apply.

A lower Assessed Value does not always lower the tax bill. In Michigan, taxes are generally based on Taxable Value. If Taxable Value is already below Assessed Value, a reduction in Assessed Value may not create savings unless it also brings Assessed Value below Taxable Value or changes the Taxable Value calculation.

Using the 1.56% countywide planning estimate, a $10,000 reduction in Taxable Value would roughly equal $156 per year before local differences. This is only an estimate. Your actual result depends on your local millage, school district, special assessments, and whether the board changes Taxable Value.

If the March Board of Review does not resolve the issue, some owners may have further review rights at the Michigan Tax Tribunal or, for certain classification issues, the State Tax Commission. The deadline and filing body depend on property type and issue, so keep the Board of Review decision letter and calendar the next state deadline immediately.

How TaxSauce helps

TaxSauce helps you slow the process down and make it more understandable. We help read the Notice of Assessment, identify the official reason that fits your facts, and organize the evidence around what the March Board of Review can actually decide.

For a Valuation / Assessed Value / True Cash Value issue, TaxSauce can help estimate the value implied by your assessment, compare it with sales evidence, and prepare a clear comparable-sales summary. You review the sales and decide which evidence you want to use.

For non-value issues, TaxSauce helps separate the questions. A Taxable Value calculation issue, exemption denial, classification concern, or record-card mistake should not be buried inside a general complaint about high taxes.

TaxSauce does not promise a reduction, guarantee that a city or township will accept a filing, or replace the local assessor's instructions. You remain responsible for reviewing the packet, signing where required, and submitting it to the right city or township by the local deadline.