DC has an equalization appeal that runs on published assessed values.
The law and the data both work here. DC gives you an equalization ground, so you can argue from what comparable properties are assessed at rather than needing sale prices. Limited mainly by size.
So District of Columbia gives you a ground that runs on published assessed values rather than on sale prices. You're not showing what your house would sell for. You're showing that homes genuinely like yours are assessed lower than yours is, using numbers the county already publishes.
Now that matters more than it sounds, because it means a state keeping sale prices private doesn't stop you. Illinois, Texas, New York, New Jersey, Pennsylvania, New Hampshire, Kansas, Massachusetts and DC all have some version of it, and honestly it's usually the stronger argument even where sale prices are public.
April 1, needs re-checking for 2027 We have flagged this one to re-verify, so check it against your own notice or your county's site before you rely on it.
Miss it and you generally wait a year, so honestly the date matters more than the paperwork does.
And wherever you are, the single most useful thing you can do today is go find your assessment notice and read the date printed on it. That's what starts your clock, it's usually a much shorter window than people expect, and there's no getting it back once it's gone.
So we only turn a state on after reading its appeal rules and its actual board decisions, so that what we tell somebody is right rather than generic. That takes a few days per state and it's honestly the reason our answers are worth anything.
In the meantime our free check runs in Washington, Illinois and Oregon. If you leave your email on the check page we'll write to you the day District of Columbia goes live, and not before.
Also, there's one move that has nothing to do with appealing and that a lot of people miss entirely. Most states take exemptions off your bill before any of the value arithmetic happens, starting with a homestead exemption if you actually live in the house, and usually extra ones for owners over 65, for veterans, and for people with disabilities. They're often worth more than an appeal win, they carry forward year after year rather than needing to be re-won, and plenty of people who qualify have never filed for them. Your county assessor's website lists what's available where you live, and it costs nothing to look.
We screened all fifty states and DC on the same two questions. Does winning a lower market value actually lower your bill, or is there a cap sitting in between? And can the evidence even be assembled from public records?
This comes from our own fifty-state screen, which checked each state's cap structure, whether sale prices are public, whether an assessment-based argument exists, and how many appeals actually get filed. Where we quote an appeal count it came from the state or county that published it. If you spot an error, please write to hello@propertytaxbuddy.com and we'll correct it and say what changed.