Your assessed value and how to apply for an abatement

How assessed value differs from market value, how to check your property record, the abatement deadline, appeals to the Appellate Tax Board, and why you keep paying while you wait.

Home value · Last updated 2026-10-29

Key points

Assessed value is the town’s estimate of fair cash value as of January 1 before the fiscal year. Compare it with sales of similar homes around that date, not with today’s market.
Check the property record first. Errors in living area, bathrooms, finished basement or condition are the clearest grounds for an abatement.
The application is due by the date the first installment of the actual tax bill is due. In Boston, for fiscal 2027, that is February 1, 2027.
Keep paying every bill on time. If the year’s tax is over $5,000, an appeal can fail unless the tax was paid in full without interest.

Assessed value versus market value

Massachusetts assessors set the fair cash value of each property as of January 1, and that value is used for the fiscal year that begins the following July 1. Fiscal 2027, for example, runs from July 1, 2026, to June 30, 2027, and its bills reflect values as of January 1, 2026.

The city values every property at once from sales data and its own records. A home can be assessed above or below what it would sell for today simply because the market moved after January 1, or because the record is wrong. The statute allows an abatement when a property is assessed above its fair cash value, is taxed more than its fair share compared with others, or is placed in the wrong class.

How the bill itself is built, including the tax rate, the residential exemption and billing dates, is in our property tax guide.

Check your property record

Every assessors’ office keeps a record for each parcel, often called the property record card. In Boston it is on the Assessing Department’s property lookup. Compare it line by line with the house.

Then look up similar homes nearby in the same database. If they carry lower values for the same features, that supports a claim that your assessment is out of proportion. To reduce a bill that has already been issued, the route is an abatement application filed on time.

Living area, and whether a basement or attic is counted as finished
Bedrooms, full baths and half baths
Year built and any renovation on record
Condition and quality grade
Lot size, garage or parking, and outbuildings
For a condo: the unit’s area, floor and parking

The abatement deadline

Under state law, the application must be filed with the assessors on or before the last day for paying, without interest, the first installment of the actual tax bill. Check the due date printed on your town’s actual bill. Boston’s fiscal 2027 window opens after the third-quarter bill is issued and closes on February 1, 2027.

The application uses a form approved by the Commissioner of Revenue, State Tax Form 128. In Boston, the abatement application and the Information Requisition Form are available through the property lookup’s Taxes and Exemptions section, and are filed by mail or in person at City Hall, Room 301.

An application mailed first class within the United States, properly addressed, counts as filed on the postmark date; the statute also covers alternative private delivery services allowed by the Department of Revenue. For any other method, confirm when it counts as delivered. If the deadline falls on a weekend or legal holiday, it moves to the next business day. You may apply if you are the person assessed, if you acquired the property after January 1, or if you are a tenant who pays more than half the tax under your lease.

After you file

Assessors may ask in writing for information about the property, such as rents or the terms of a sale. Under §38D the usual deadline is 60 days, and failing to comply can cost you a later appeal. Boston asks for its Information Requisition Form with the application and says it will deny the application if the information is not provided within 30 days of filing.

The assessors have three months from filing to act. If they do nothing, the application is deemed denied at the end of that period, unless you agree in writing to extend it. You receive written notice of the decision. If you disagree, you may appeal to the Appellate Tax Board within three months of the decision or the deemed denial.

Step	Deadline	Law
File the abatement application	By the due date of the first actual-bill installment (Boston FY2027: February 1, 2027)	c.59 §59
Answer the assessors’ written request	Usually within 60 days; Boston: 30 days from filing	c.59 §38D
Assessors decide	Within 3 months of filing, or the application is deemed denied	c.59 §64
Appeal to the Appellate Tax Board	Within 3 months of the decision or deemed denial	c.59 §64, §65

Keep paying while you wait

Filing does not pause your bill. Pay every installment on time; late payments accrue interest. If the bill is later reduced, ask the collector’s office how the overpayment will be refunded or credited.

At the appeal stage the law adds a condition. If the tax on the parcel for the full year is more than $5,000, it will not be abated on appeal unless the full tax was paid without incurring interest. The statute offers an alternative based on the average tax of the three preceding years; ask a tax professional before relying on it.

Building your case

For a disagreement about value, evidence beats argument. At the Appellate Tax Board, the informal procedure is available only if both sides elect it, and choosing it means giving up further appeal except on questions of law. For a home assessed at more than $20,000, the assessors can insist on the formal procedure. Many owners prepare the application themselves; for an appeal, consider a tax attorney or an appraiser.

Sales of similar homes that closed near January 1 of the valuation year, with the differences adjusted. Sales long after that date reflect a different market.
Corrections to the record, with photos or plans.
Photos and contractor estimates for condition problems the record does not show.
A recent appraisal, if you have one, with its effective date.
If you bought near the valuation date in an arm’s-length sale, your closing documents.

General information for Massachusetts property owners, current as of the date shown. It is not legal or tax advice. Deadlines are set by statute and by your town’s billing schedule; confirm them with your assessors’ office, and consult a tax attorney for an appeal.