How to look up your home's assessment history year by year

Last updated 2026-07-10

Why does your assessment history matter at all?

One year of data tells you almost nothing. The trend tells you everything.

Most homeowners only look at their assessment when the annual notice lands and the number feels off. Fair enough. But a single figure floating in space can't tell you whether you're being treated fairly. You need the arc.

Say your assessment was $280,000 three years ago, $295,000 two years ago, and then jumped to $370,000 this year. That's a 25% single-year spike on a property that had been rising at about 5% a year. That pattern is evidence. It's the kind of thing that wins an appeal, or at least forces a real conversation with the assessor's office.

The history also shows whether you're on a consistent reassessment cycle or getting hit selectively. Some counties reassess every property every year. Others run two- or three-year cycles. If the neighbors who sold recently got reassessed and you didn't, or the reverse, the history document is what shows it.

There's a budgeting reason too. Tax bills lag assessments by six to twelve months in most states, so the spike you see today is the bill you pay next year. Catching it now buys you time to appeal before that bill locks in ^[1].

Where can you find your property's assessment history for free?

The county assessor's office is the primary source, and most of them now post historical data online for free. Here's the path that works almost everywhere:

1. Go to your county assessor's website. If you don't know it, search "[your county name] assessor" and click through to the .gov or official county domain. 2. Find the property search tool, usually labeled "Property Search," "Parcel Search," or "Real Property Records." 3. Search by address, owner name, or parcel number (APN or PIN). 4. Open the property detail page. Look for tabs or links labeled "Assessment History," "Value History," "Tax History," or "Parcel History." 5. Download or screenshot the table showing assessed values year by year.

Some counties show only the current year on the main detail page and bury the history behind a secondary tab. Cook County, Illinois, keeps a separate "Assessment History" view reachable from the parcel detail page on the Cook County Assessor's portal ^[2]. Los Angeles County's Assessor portal breaks out assessed land value and improvement value separately by year, which matters because Proposition 13 holds California annual increases to 2% until a change in ownership ^[3].

If the county site comes up empty, your next stops are these:

• The county appraisal district website (this is the norm in Texas, where the appraisal district is separate from the tax assessor-collector)
• Your state's centralized property tax portal (many states run one; see the section below)
• The county auditor or recorder of deeds, who may hold older records
• A formal public records request under your state's open records law if the online data is thin ^[4]

Third-party sites like Zillow and Redfin sometimes surface assessed value history pulled from public records. Use those as a quick cross-check, never as the source you cite in an appeal. The official assessor record always controls.

How far back does assessment history typically go?

It varies a lot. Most county assessor systems keep at least five years of history online, and many go back ten or fifteen. Older records usually survive on paper or microfiche at the assessor's office even when they're not posted.

States with stable constitutional assessment limits keep the longest, most detailed records. California counties, under Proposition 13 (enacted 1978), have to track the factored base year value separately from any enrolled changes, so records often reach back decades ^[3]. In New York City, the Department of Finance publishes tentative and final roll data going back several years through its public property portal ^[5].

For an appeal, three to five years is plenty. Anything older is more useful for estate planning or a refinancing argument than for an administrative hearing. Boards and tribunals rarely weigh data older than five years unless there's a specific legal reason.

A few counties migrated to new software and lost easy access to older online records along the way. If you hit a gap, call the assessor's office and ask whether older valuations sit in their archive system and whether staff can pull them. Most offices do it without charge.

What data fields should you look for in the history record?

A complete history record should show each of these fields for every year. Not every county displays all of them, but the more you get, the more you can catch.

Field	What it means
Tax year	The year the value applies to (often one year ahead of the bill date)
Assessed value (total)	The value the assessor placed on land plus improvements combined
Land value	Assessed value attributed to the lot alone
Improvement value	Assessed value of the structure(s)
Exemptions applied	Homestead, senior, veteran, and the like that reduce the taxable base
Taxable value	Assessed value after exemptions, the number the tax rate applies to
Assessment ratio	Some states assess at a fraction of market value (for example, 10% in Alabama) [6]
Sale date / sale price	If a recorded sale triggered a reassessment

Land value and improvement value broken out separately is the pair worth hunting for. If the assessor quietly shifted value from land to improvements (or the reverse) with no explanation, that can signal a data-entry error or a reassessment triggered by a permit that got mis-coded.

Exemptions are easy to miss and expensive to lose. If a homestead exemption that applied for ten years vanished last cycle, your taxable value can jump even when the assessed value barely moved. The history record is how you catch that quietly.

How do you find assessment history for specific counties?

Here are direct paths for some of the most-searched counties in the country. The process rhymes everywhere; only the interface changes.

Cook County, Illinois: Go to the Cook County Assessor's website (cookcountyassessor.com), run the property search, and on the parcel result page find the "Assessment History" section. It shows triennial reassessment values across multiple cycles ^[2]. The tax bill side is a separate office: the Cook County Treasurer handles payments and bill history. See our guide to the cook county tax assessor tax bill for the full picture.

Los Angeles County, California: The LA County Assessor portal (assessor.lacounty.gov) lets you search by AIN (Assessor's Identification Number) or address and shows assessed value history with land and improvement broken out. Prop 13 means the history usually shows a flat 2% annual bump with a jump at a sale date ^[3]. Our la county property tax guide covers the appeal process there.

Montgomery County, Maryland: The State Department of Assessments and Taxation (SDAT) runs assessments for all Maryland counties through its Real Property Data Search. Search by address to get the three-year cycle history. Montgomery County owners get reassessed on a three-year cycle with a 10% annual cap on assessed value increases ^[7]. See our montgomery county property tax breakdown.

Bexar County, Texas: The Bexar Appraisal District (bcad.org) handles assessments separately from the tax assessor-collector. Search its parcel tool by owner name, address, or property ID for year-by-year appraised value history. Texas caps homestead appraisals at 10% annual increases ^[8]. Our bexar county tax assessor guide has the protest calendar and form links.

Gwinnett County, Georgia: The Gwinnett County Tax Assessor (gwinnettcounty.com) runs a parcel search that shows historical assessed values. Georgia assesses at 40% of fair market value, so the assessed value online is not the market value the assessor thinks your home is worth ^[9]. The gwinnett county tax assessor article explains how to convert that number before comparing to sales.

Hennepin County, Minnesota: The Hennepin County online property search (hennepin.us) shows estimated market value history and assessed value history as separate fields, which matters because Minnesota uses an exclusion formula rather than a straight assessment ratio. See hennepin county property tax for more.

New York City: The NYC Department of Finance property portal (nyc.gov/finance) shows current and prior-year assessed values. For full roll history, the NYC Open Data portal publishes annual property valuation files. The nyc property tax guide covers the four property tax classes and how they shape your history read.

Does your state have a centralized property tax database you can use?

Some states consolidate property data at the state level. That's a gift when the county website is clunky or out of date.

• Maryland: SDAT's Real Property Data Search (sdat.dat.maryland.gov) covers all 24 jurisdictions in one interface and shows assessment cycle history ^[7].
• Connecticut: The Office of Policy and Management posts Grand List data by town, though detail varies by municipality.
• New Jersey: The Division of Taxation's property tax pages link to county assessment records, but full parcel history still lives at the county level.
• California: No statewide parcel search exists. Each of the 58 county assessors runs its own database. The California Department of Tax and Fee Administration publishes aggregate assessment roll statistics annually ^[10].
• Texas: No state-level parcel portal. Each of the 254 county appraisal districts operates independently, though many are reachable through the Texas Comptroller's Property Tax Assistance Division (comptroller.texas.gov) ^[8].
• Florida: The Florida Department of Revenue links to each county property appraiser from its property tax page, but every county runs its own search.

The Lincoln Institute of Land Policy keeps a 50-state database of property tax laws and assessment practices. It won't link you to an individual parcel, but it tells you what fields to expect in your state's records ^[11].

How do you read a year-over-year history table to spot a problem?

You have the history in hand. Now work it in five moves.

First, calculate the percentage change for each year. If your assessed value went from $310,000 to $388,000 in one year, that's a 25.2% increase. Write it down.

Second, compare that increase to what sales in your neighborhood actually did. If nearby homes sold for about 10% more than the year before, a 25% assessment jump is out of sync and worth contesting.

Third, hunt for the trigger. Did the office pull a permit on your home? Did the property sell and get reassessed at the sale price, which is common in states without Prop 13-style limits? Check whether a permit got filed for work you never did. That data error is more common than you'd think.

Fourth, check whether land value and improvement value moved together. A big jump in improvement value on a house where no permits were pulled is a flag worth questioning.

Fifth, compare your increase to what neighbors saw. Many county portals let you pull neighboring parcels with the same search tool. If your assessment went up 25% and houses on the same block went up 8%, you have a structural inequity argument, which in many states is an independent ground for appeal separate from market value ^[12].

The TaxFightBack DIY appeal kit walks through exactly this analysis with form templates you take straight to your assessor's informal review, and you keep 100% of whatever reduction you win.

One honest caveat. If your history shows your property was under-assessed for years and the assessor is now correcting toward market value, that context works against you. You can still appeal, but you're arguing from a weaker spot. Knowing that going in saves you wasted time.

Can you request your assessment history in writing if it's not online?

Yes. Every state has an open records law that covers assessment data. The name changes: Florida has the Government in the Sunshine Law, Texas has the Public Information Act, California has the Public Records Act. The federal Freedom of Information Act (FOIA) doesn't reach county assessors because they're state entities, but the state equivalents do ^[4].

To request assessment history in writing:

1. Address the request to the county assessor's office (or the appraisal district in Texas). 2. Identify the parcel by address and, if you have it, the APN or parcel ID. 3. Specify the years you want (for example, "assessed values for tax years 2015 through 2025"). 4. Ask for land value and improvement value separately if you want that breakdown. 5. Ask whether any fees apply for copying or retrieval.

Most open records laws require a response within 5 to 10 business days, though some allow extensions. Texas requires a response within 10 business days ^[4]. California requires a response within 10 days ^[13]. Florida requires records to be provided "promptly" with no fixed number of days.

Fees for printed records are usually nominal (10 to 25 cents per page) or waived for small requests. Electronic records are typically free. If an office claims the history is confidential, that's almost certainly wrong for basic assessed values, which are public record in every state.

How does assessment history connect to your tax bill history?

These are two different records, and knowing which one you're holding saves confusion.

Your assessment history shows the value the assessor put on your property each year. That value feeds the tax math but isn't the bill.

Your tax bill history shows what you actually paid or owed after the tax rate hit your taxable value and exemptions came off. Both are public, but they often live in different places. The assessor holds the assessment history. The county treasurer or tax collector holds the payment history.

On some county portals, both sit on the same parcel detail page. On others, you jump to a separate "Tax Payments" or "Tax Bills" page using the same parcel number. In Cook County, the Assessor handles value and the Treasurer handles bills, two separate sites ^[2]. In los angeles county property tax, the Assessor and the Treasurer-Tax Collector are also separate offices with separate portals.

For an appeal you almost always need the assessment history (the value), not the bill history (the payment). But the bill history is handy for confirming your exemptions actually applied each year, because they sometimes drop off without notice and you overpay without knowing.

If you're making an online tax payment and want to cross-check your tax history at the same time, see our online tax payment for property guide for how the payment portals are laid out.

What should you do once you have the history and spot a problem?

Move fast. Most states measure appeal deadlines in weeks from the date your notice arrives. Miss it by a day and you usually forfeit your right to appeal that year. Deadlines commonly run 30 to 90 days after the notice date, but they vary by state and sometimes by county ^[1].

Here's the sequence:

1. Pull the assessment history and calculate the year-over-year change. 2. Compare it to recent sales of comparable homes nearby (comps). Many county portals include sales data, and the assessor's own comparables are often your strongest evidence. 3. Check for data errors first: square footage, bedroom and bathroom count, lot size, year built. A wrong square footage on the assessor's card is the easiest win and often the fastest fix. 4. File for an informal review or formal appeal, depending on your state's process. Many counties offer an informal meeting with an appraiser before the formal board. 5. Bring your assessment history table, your comps, and any data-error documentation to the review.

You don't need a lawyer or a contingency firm for a residential appeal. The evidence is public, the process is administrative rather than a courtroom, and filing fees, where they exist, usually run under $50. What you need is organized documentation, which is exactly what the assessment history gives you.

Are there any limits on how much your assessment can change in one year?

Yes. Many states cap annual increases by statute, and your history should reflect the cap. If the history shows a jump that blows past it, that overage is itself a ground for appeal.

State	Cap type	Cap limit	Source
California	Annual increase cap (Prop 13)	2% per year (or inflation, whichever is lower)	CA Const. Art. XIII A [3]
Maryland	Annual increase cap	10% per year on assessed value	MD Code Tax-Prop § 8-103 [7]
Texas	Homestead cap	10% per year on appraised value	TX Tax Code § 23.23 [8]
Florida	Homestead cap (SOH)	3% or CPI, whichever is lower	FL Const. Art. VII § 4 [14]
Michigan	Taxable value cap	5% or inflation, whichever is lower	MI Const. Art. IX § 3
Georgia	No statewide annual cap	N/A; 40% ratio applies	GA Code § 48-5-7 [9]
New York	No statewide residential cap	Class-specific limits in NYC only	NY RPTL [5]

Caps usually apply to homestead or owner-occupied property and reset when the home sells. The sale price becomes the new base year value, and the cap restarts from there. So if you bought recently, your first year's assessment may reflect the sale price and look like a big jump in the history even though it's legal under the reset rule.

Knowing your state's cap before you read the history tells you right away whether the number is even contestable on those grounds.

Frequently asked questions

Is property assessment history public record?

Yes, in every U.S. state. Assessed values are public information maintained by county assessors and appraisal districts. No state treats the assessed value of real property as confidential. You can request the data in person, by mail, or through most county websites at no cost, and open records laws back up that right if an office gives you trouble.

How do I find my home's parcel number to look up assessment history?

Your parcel number (also called APN, PIN, or parcel ID) is on your property tax bill, your deed, or your title insurance policy. If you don't have those handy, search your address on the county assessor's website and the parcel number appears in the results. Write it down; you'll use it every time you deal with the assessor's office.

What if my county's website doesn't show historical assessment data?

File a written public records request with the assessor's office citing your state's open records law. Most states require a response within 5 to 10 business days. Older records that predate the county's digital system may sit on paper or microfiche in the archive, but staff can usually print them for a small per-page fee or no charge for small requests.

Can I look up assessment history for a neighbor's property?

Yes. Assessment data is public for every parcel, not only your own. Looking at neighbors' histories is useful before an appeal because it shows whether your assessment jumped more than comparable homes nearby, which is an equity argument many states explicitly allow as independent grounds for appeal.

How many years of history do I need for a property tax appeal?

Three to five years covers almost any residential appeal. You're mainly showing whether this year's value is an anomaly or in line with prior trends, and whether it tracks actual market changes. Anything beyond five years rarely gets weight in an administrative hearing unless there's a specific factual dispute about a prior base year value.

What's the difference between assessed value history and market value history?

Assessed value is the number the county puts on your property for tax purposes. Market value is what a buyer would pay in a normal sale. In states that assess at a fraction of market value (Georgia at 40%, Alabama at about 10%), the assessed value always runs lower than market value. The history record shows assessed value; to get implied market value, divide by your state's assessment ratio.

Does a home sale reset the assessment history and start a new base year?

In most states, yes. A sale triggers reassessment to or near the sale price, and annual change caps (where they exist) restart from that new base. In California under Prop 13, the sale price becomes the new factored base year value and the 2% annual cap runs forward from there. In states without caps, reassessment at sale is still common, but the prior history stays useful for equity comparisons.

What if I think my assessment history shows a data error?

Data errors are the fastest appeals to win. If the assessor's record shows the wrong square footage, wrong number of bathrooms, or a permit for work you never did, document the correct figures with a tape measure, floor plan, or permit records from the building department. Bring that to an informal review; most assessors correct a clerical error without a formal hearing.

Can a landlord or tenant look up the assessment history of a rental property?

Anyone can look up the assessment history of any parcel; there's no ownership requirement for public records. Tenants in some rent-regulated jurisdictions use assessment and tax bill histories to challenge rent increases tied to property tax changes. Landlords use the history to verify expenses for financing or sale purposes.

How does assessment history differ from Zillow's estimate history?

Zillow's Zestimate history is a proprietary algorithmic estimate of market value, not an official government record. Assessors don't use it and boards of appeal give it no evidentiary weight. The official assessment history from the county assessor's parcel record is the document that matters for appeals, exemption audits, and any legal or financing purpose.

How do I find assessment history for a property in Texas, where the appraisal district is separate?

In Texas the county appraisal district (CAD) holds the appraised value history, not the tax assessor-collector. Search your county's CAD website (BCAD for Bexar County, HCAD for Harris County) by owner name, address, or property ID. The CAD site shows appraised value history going back at least five years for most districts. The Texas Comptroller's site links to all 254 CADs.

Can I use assessment history to appeal a reassessment after buying a home?

Yes, but the argument is harder if the reassessment reflects your actual purchase price. You'd need to show the purchase price doesn't represent fair market value (a distressed or non-arm's length sale, say) or that the assessor applied the sale price incorrectly. The prior history sets context, but at purchase your stronger argument usually turns on the accuracy of the sale transaction itself.

Are there third-party tools that aggregate assessment history across counties?

Some exist. PropStream, ATTOM Data, and CoreLogic aggregate county assessment data for investors and professionals, usually behind a paid subscription. For a homeowner appealing their own assessment, the county's free portal gives you everything you need. Third-party data can lag six to twelve months and occasionally carries errors the official record doesn't, so verify against the assessor's own record before using it in an appeal.

Sources

1. NCSL, Property Tax Assessment Limits: Property tax bills lag behind assessments by up to 12 months in many states; assessment cycle timing varies by state.
2. Cook County Assessor's Office, Property Search: Cook County Assessor provides assessment history and appeal history by parcel on a public portal; Cook County Treasurer handles bill history separately.
3. California State Board of Equalization, Property Tax: Proposition 13 (CA Const. Art. XIII A) caps annual increases in a property's factored base year value at 2% until a change in ownership.
4. Texas Attorney General, Public Information Act: State open records laws cover assessment data; the Texas Public Information Act requires a response within 10 business days.
5. NYC Department of Finance, Property Tax: NYC Department of Finance publishes annual property assessment rolls and value history through its public portal.
6. Alabama Department of Revenue, Property Tax: Alabama assesses residential property at 10% of fair market value as the assessment ratio for tax purposes.
7. Maryland SDAT, Real Property Assessments: Maryland assesses on a three-year cycle with a 10% annual cap on assessed value increases under MD Code Tax-Prop § 8-103.
8. Texas Comptroller, Property Tax Assistance Division: Texas Tax Code § 23.23 caps annual appraised value increases at 10% for homestead properties.
9. California Department of Tax and Fee Administration: California has no statewide parcel search; aggregate assessment roll statistics are published at the state level while each of the 58 counties runs its own database.
10. Lincoln Institute of Land Policy, Significant Features of the Property Tax: The Lincoln Institute maintains a 50-state database of property tax laws, assessment ratios, and practices.
11. NCSL, Property Tax Assessment Limits: Many states allow appeals on grounds of assessment inequity (uniformity) separate from market value disputes.
12. Florida Department of Revenue, Property Tax Oversight: Florida's Save Our Homes amendment caps annual increases in assessed value for homestead properties at 3% or the CPI change, whichever is lower.