State Guide

How to Appeal Your Property Taxes in Wyoming (2026 Guide)

Published August 27, 2026

A Wyoming property tax appeal doesn't run on a calendar date. It runs on a clock that starts when your county assessor drops your assessment schedule in the mail — and it gives you thirty days. Miss that window and the value is locked in for the year, no matter how far off it is.

The Wyoming deadline: 30 days from your assessment schedule

Under W.S. 39-13-109(b)(i), anyone contesting an assessment must file a written statement of the reasons the assessment is incorrect — with the county assessor, not the board — no later than 30 days after the date of the assessment schedule. A statement mailed or sent electronically counts as timely if it's postmarked or transmitted inside those 30 days, so you don't have to get it in the assessor's hands by day 30.

The starting gun is fixed even though the deadline isn't: W.S. 39-13-103(b)(vii) requires assessors to send schedules on or before the fourth Monday in April. That was April 27, 2026, and it's April 26, 2027 — so in a typical county the window closes in late May. If you're reading this after your 2026 window shut, the fix is a calendar entry: watch the mail in late April 2027 and count 30 days from the date printed on the schedule, not from the day you happened to open it.

How Wyoming assesses your home

Wyoming taxes a fraction of your home's value. Your taxable (assessed) value is 9.5% of fair market value under W.S. 39-13-103(b)(iii)(C) — a home the county says is worth $600,000 carries a $57,000 assessed value, and the mill levy applies to that $57,000. What you appeal is the fair market value, the 100% figure. Win a lower one and the 9.5% falls with it.

Your schedule has to show you both numbers and more. W.S. 39-13-103(b)(viii) requires it to carry the current and prior year's fair market value, the assessment ratio, last year's taxes, an estimate of this year's taxes, an estimate of what the residential exemptions save you, and a statement of the process to contest the assessment. Two years of value side by side is the single most useful thing on the page — a jump that outruns your local market is exactly the case an appeal is built on.

Category	Wyoming
Assessment basis	Taxable value = 9.5% of fair market value (§39-13-103(b)(iii)(C))
Appeal deadline	30 days from the date of your assessment schedule (§39-13-109(b)(i))
When schedules mail	On or before the fourth Monday in April (§39-13-103(b)(vii))
Where you file	Written statement of reasons, with your county assessor
Assessment cap	4%/yr growth cap on residential structure and land, as exemptions (§39-11-105(a)(xliii), (xliv))
Homeowner exemption	25% of the first $1M of fair market value, owner-occupied (§39-11-105(a)(xlvi))
Can the board raise your value?	No — it may only affirm or find for you and remand (§39-13-109(b)(i))

The 4% cap — and why a recent purchase changes the math

Wyoming caps residential growth, but it does it through the exemption statute rather than a valuation limit. W.S. 39-11-105(a)(xliii) exempts any assessed value of a single-family residential structure above last year's assessed value plus 4%, and (xliv) does the same for the improved land underneath it.

The resets matter more than the rate. The structure cap does not apply if the increase comes from new construction or structural changes, or if you acquired the property during the prior calendar year — and the land cap drops away on that same acquisition trigger. So if you've owned for years, the cap may already be holding your assessed value below market, and a comparable-sales win mostly protects your future baseline. If you bought recently, you have no cap protection at all this year, and a lower fair market value cuts your bill immediately.

Separately, W.S. 39-11-105(a)(xlvi) exempts 25% of the first $1,000,000 of fair market value of an owner-occupied single-family home and its improved land. Starting in tax year 2026 you have to actually live there at least eight months of the year (with an active-duty military exception), which means filing an affidavit — confirm the current form and its due date with your county assessor or the Department of Revenue, since that piece is set by rule, not by the statute.

Wyoming's best-kept appeal advantage: the sales data

Wyoming is a non-disclosure state — the statement of consideration filed with a deed is "not a public record" and is held confidential (W.S. 34-1-142(e)). You can't look up what the house down the street sold for. That's the ordinary frustration of building a Wyoming case.

Appealing is the statutory way through it. That same subsection carves out an exception for an owner reviewing or contesting an assessment, and W.S. 39-13-109(a)(i) spells out what you get: the statements of consideration for properties of like use and geographic area that were available to your assessor, the parcels the assessor actually relied on, and — on request — a written statement of why a particular property was not used. On top of that, §39-13-109(b)(i) requires both sides to exchange evidence, documents, and witnesses no later than 30 days before the hearing, and the assessor must specifically identify the sales used to value your property.

That is a genuinely strong position. Ask for it in writing, early, and build your case on the same closed sales the county used.

What happens after you file

Your statement goes to the assessor, who forwards a copy to the county clerk as clerk of the county board of equalization. You'll get a recorded hearing, and the board must issue specific written findings and conclusions no later than October 1.

The downside risk is unusually low here. Under §39-13-109(b)(i) the county board "may affirm the assessor's valuation or find in favor of the taxpayer and remand the case back to the assessor" — it has no authority to raise you on your own appeal. What it does have is a presumption in favor of the assessor's value, which you're entitled to rebut with any relevant evidence, including expert testimony. Lose, and the next rungs are the State Board of Equalization (W.S. 39-11-102.1(c)) and then district court (§39-13-109(b)(iv)); the State Board sets its own filing window by rule, so check it as soon as you have the county board's order.

One change worth watching

In November 2024 Wyoming voters ratified Constitutional Amendment A (2023 SJ0003), which split residential real property into its own class under Art. 15, §11 and authorized a subclass for owner-occupied primary residences. But §11(b) leaves the percentage to the legislature, and the statute still assesses residential property at the same 9.5% as all other non-mineral, non-industrial property. Until that changes, 9.5% is your number.

Get your case built

Wyoming's clock is short and it starts without warning. PROppeal pulls licensed comparable sales for your address, applies Wyoming's 9.5% rule, factors in whether the 4% cap changes what a win is actually worth, and gives you a straight read on whether your assessment is out of line — so you're ready the week your schedule arrives, not scrambling 30 days later.

Property tax rules and deadlines vary by jurisdiction and can change — verify with your county before relying on this.