Property Tax on Deer Isle / Stonington, ME: Two Towns, Two Rates

Two Assessing Offices, Not One

Because Deer Isle and Stonington are separate towns, they maintain separate property tax records and separate assessing offices — the Town of Deer Isle's own government site hosts a dedicated "Property Tax & Assessing" page, and the Town of Stonington's own site hosts a separate "Tax Information, Tax Documents & Tax Resources" page. A buyer or agent pulling a specific parcel's current assessed value, mil rate, and tax bill should go to whichever town's own office actually covers that parcel — the two offices do not share one combined database or one combined rate.

This is a meaningfully different structure than a single-town market elsewhere on this site, and it is easy to get wrong by assuming "Deer Isle/Stonington" behaves like one municipality with one tax rate. It does not.

Both Towns Raised Taxes in 2025 — the Confirmed Direction, Not a Confirmed Rate

A June 26, 2025 Island Ad-Vantages report (Penobscot Bay Press, reported by Ben Barrows and Will Robinson) confirms that both towns saw property tax increases for that cycle. Per that report, officials in both towns said the increases were driven by higher Community School District 13 and Hancock County budgets — meaning the pressure came from shared, regional cost centers (the school district both towns fund, and the county), not from either town's own municipal spending alone.

This page does not state the specific mil rate or percentage increase for either town, because the article's full figures sit behind a subscription paywall that this research pass could not access. A build agent or buyer should not repeat a specific number without confirming it directly against each town's own current assessing records — the confirmed, durable fact here is the direction (both towns' rates rose) and the driver (school district and county budgets), not a dollar figure.

What Drives the Bill: CSD 13 and Hancock County

Community School District 13 (CSD 13) is the shared elementary/K-8 district covering both Deer Isle and Stonington, with its own school board and its own budget that both towns fund — a real, currently active regional cost center, evidenced by reporting on a CSD 13 board budget vote and calendar approvals. Hancock County's own county budget is the second shared driver named in the 2025 tax-increase reporting. Because both of these sit above the level of either individual town's own municipal budget, a rising CSD 13 or county budget can push both towns' tax rates upward in the same cycle even if neither town's own town-level spending changed dramatically — worth understanding before assuming a rate increase reflects purely local town decisions.

Assessed Values Differ Between the Two Towns Too

Beyond the rate itself, the underlying assessed-value base differs between the two towns. Zillow's own current home-value index puts Deer Isle (04627) at roughly $415,101 against Stonington (04681) at roughly $508,686 — a real, sourced gap that will affect the actual dollar tax bill on comparably-taxed properties in each town, independent of the mil rate itself. A buyer comparing a specific Deer Isle parcel against a specific Stonington parcel should expect the tax math to differ on both the rate and the base.

The Maine Homestead Exemption Can Reduce Either Town's Bill

One statewide program applies in both towns and is worth knowing before budgeting a bill: Maine's Homestead Exemption Program reduces a home's taxable value by up to $25,000 for a genuine, permanent, year-round primary residence — not a seasonal camp or second home — provided the owner has held Maine residency for the 12 months prior and files an application with the relevant town by April 1. The $25,000 figure is adjusted by each municipality's own certified assessment ratio, so the actual dollar reduction can differ between the Town of Deer Isle and the Town of Stonington even at the same nominal exemption. Recent state legislation extends the full, unadjusted $25,000 exemption specifically to homeowners 65 and older or veterans, regardless of the municipality's assessment ratio, starting with property tax years beginning April 1, 2026. This page does not state either town's own current certified assessment ratio, since neither was independently confirmed this research pass; ask the relevant assessing office directly when applying.

Before You Budget a Tax Bill

Put together, honestly: this page confirms that Deer Isle and Stonington are two separate taxing jurisdictions, that both raised rates in the 2025 cycle, and that CSD 13 and Hancock County budget growth were the stated drivers — but it does not state a specific current mil rate for either town, because that figure was not independently confirmed to a reliable, current number this research pass.

Before budgeting a purchase, contact the Town of Deer Isle's own assessing office or the Town of Stonington's own assessing office directly (whichever applies to the specific parcel), and ask for the current mil rate, the parcel's current assessed value, and the current homestead exemption status if applicable. Nothing on this page is tax or legal advice.