Massachusetts must assess at full and fair cash value — and when your third-quarter "actual" tax bill arrives around New Year's, you have until February 1 to file a Form 128 abatement application with your local Board of Assessors. It's free, and our tools help you build the comps that win.
Mailed around December 31, it shows your FY2026 assessment — the town's opinion of fair cash value as of January 1, 2025. That's the number you're testing.
Pull your property record card (free from the assessors or their Vision/AxisGIS portal) and comparable sales. MassGIS publishes the statewide parcel database free — see our data notes.
File with your local Board of Assessors — received or USPS-postmarked by the due date of the third-quarter bill. Attach your comps worksheet and record-card corrections.
Assessors have 3 months to act (silence = denial). You then have 3 months to appeal to the ATB — informal small-claims style procedure for most homes.
To preserve your abatement and ATB appeal rights you must pay every installment on time and in full — the appeal rides alongside payment, and a win comes back as a refund with interest. And the Feb 1 deadline cannot be extended by the assessors for any reason (M.G.L. c. 59, § 59).
Everything runs in your browser — we never see or store your property data.
Massachusetts rates are set per $1,000 of value — a $11.40 rate means enter 1.14 above. Rates vary widely by town (roughly $5–$18 per $1,000); check your bill. Statewide average effective rate ≈ 1.14%. Estimates only; not tax advice.
Enter sales of similar homes near the January 1 valuation date (your town's Vision/AxisGIS portal publishes sales; MassGIS has the whole state). The worksheet computes price per square foot and a suggested fair cash value.
| Address | Sale Date | Sale Price ($) | Sq Ft | $/Sq Ft |
|---|
| Item | Massachusetts Rule |
|---|---|
| Fiscal year | July 1 – June 30; FY2026 values = fair cash value as of January 1, 2025 |
| Abatement deadline | Due date of the 3rd-quarter actual bill — February 1 (Feb 2, 2026, since Feb 1 falls on a Sunday); received or USPS-postmarked; no extensions |
| Form | State Tax Form 128 — filed with your local Board of Assessors, free |
| Assessors' decision | 3 months to act — no action = deemed denied |
| Next level | Appellate Tax Board within 3 months of decision/deemed denial (informal procedure for most residential) |
| Payment rule | Pay all installments on time and in full to preserve appeal rights; wins refund with interest |
| Standard | Full and fair cash value (M.G.L. c. 59) + Proposition 2½ levy limits |
| Records | Town assessor portals (Vision/AxisGIS/Patriot) + free MassGIS statewide standardized parcel data |