Mystic, CT Property Tax: Two Towns, Two Rates
Property tax is the one topic on this site where Mystic cannot be treated like a normal single-town market, and pretending otherwise would actively mislead a buyer. Mystic is not a town. It is an unincorporated village straddling the Mystic River, split between the Town of Groton on the west bank and the Town of Stonington on the east bank, and it has no government, no charter, no mayor, no council, and no budget of its own. That means there is no such thing as "the Mystic mill rate" -- there is a Groton rate and a Stonington rate, they are calculated differently, they change on different schedules, and this research found a real, unreconciled discrepancy between the two towns' own numbers even for figures that are supposed to describe the same fire district. This page lays out what was found, in what order it matters, and exactly where it should be re-verified before anyone relies on it to make a purchase decision.
Start Here: Mystic Has No Government and No Budget of Its Own
Before any number on this page means anything, the underlying structural fact has to be understood: Mystic is a village and census-designated place, not an incorporated municipality. It has never had its own charter, its own elected officials, or its own municipal budget process. Every property tax bill mailed to a "Mystic, CT" address is actually issued by one of two separate town governments -- the Town of Groton or the Town of Stonington -- depending on which bank of the Mystic River the property sits on. This is the single most important fact on this page, because it means the question "what is the property tax rate in Mystic" does not have one answer. It has two, and they are not close to each other.
This should not be confused with two nearby places that sound similar but are governed completely differently. Old Mystic is a separate census-designated place a short distance north, also split between Groton and Stonington, but with its own fire district and its own ZIP code (06372) -- its facts do not transfer to Mystic proper and are not used anywhere on this page. Stonington Borough is a separately incorporated borough within the Town of Stonington, with its own government layered on top of the town, and it is a genuinely different real estate market with its own tax facts that also do not belong on this page. Anyone comparing tax pages across this site should treat those as three distinct markets, not variations on the same one.
The Groton Side: Town Mill Rate Plus a Mystic Fire District Add-On
A Mystic property on the Groton (west) side of the river is taxed under the Town of Groton's mill rate. Per the town's own mill-rate schedule, the base rate is 24.81 mills on the 2024 Grand List, with bills due July 1, 2025 (fiscal year 2026). Groton is governed under a council-manager system -- a Town Council and a Town Manager (John Burt at the time of this research), with a 45-member Representative Town Meeting that must approve the budget before the Council sets the mill rate -- so this rate reflects that full local budget process, not a state-set figure.
Groton's own schedule does not stop at the base rate. It separately lists a "Mystic" fire-district rate of 2.41 mills as an add-on for properties within that fire district's Groton-side boundary, and, for properties inside the Groton Sewer District specifically, an additional 0.38 mills. Adding those together, a Groton-side Mystic property's combined rate for this cited year works out to roughly 24.81 plus 2.41, plus 0.38 if the property is in the sewer district -- call it approximately 27.2 to 27.6 mills combined, depending on sewer-district status. One important caution embedded in Groton's own schedule: it also lists a separate "Old Mystic" fire-district rate of 2.50 mills. That figure belongs to the different Old Mystic village discussed above, not to Mystic proper, and this page does not apply it here -- a mistake worth flagging because the two names are easy to conflate on a quick read of the same schedule.
The Stonington Side: A Different Town Rate, a Different Fire District Figure
A Mystic property on the Stonington (east) side of the river answers to an entirely separate town government -- Stonington operates under a First Selectman and Board of Selectmen, with an Annual Town Budget Meeting and referendum rather than Groton's Representative Town Meeting structure. Bill Middleton was elected First Selectman on November 4, 2025, succeeding Danielle Chesebrough. Per the Connecticut Conference of Municipalities' Data Hub profile, Stonington's real and personal property mill rate for fiscal year 2025 was 18.18 mills, against a 2025 grand-list valuation of roughly $4,081,337,444 and a total tax levy of roughly $71.18 million.
On top of that town rate, a Stonington-side Mystic property also owes the Mystic Fire District's own Stonington-side rate, which per the district's 2024/2025 rate sheet was 1.647 mills. That same district rate sheet also lists a "basic" rate of 1.620 mills and, separately, a Groton-side rate of 2.206 mills -- a figure that matters for the discrepancy discussed directly below. Combining Stonington's 18.18-mill town rate with the district's 1.647-mill Stonington-side add-on puts a Stonington-side Mystic property at roughly 19.8 combined mills for these cited years -- noticeably lower than the Groton-side combined figure above.
A Discrepancy This Research Could Not Resolve, Disclosed Rather Than Hidden
Here is the specific inconsistency worth naming directly rather than smoothing over: the Mystic Fire District's own rate sheet reports its Groton-side rate as 2.206 mills, but the Town of Groton's own FY2026 mill-rate schedule lists the "Mystic" fire-district add-on as 2.41 mills. Those two numbers, both purporting to describe the same fire-district charge on the same side of the same river, do not match, and this research did not independently reconcile why.
The most likely explanation is that these figures come from different fiscal years -- the fire district's rate sheet is dated 2024/2025, while the town schedule is built on the 2024 Grand List for FY2026 bills due July 2025 -- rather than a genuine contradiction about the current rate. But that is an inference, not a confirmed fact, and this page deliberately does not pick one number, present it as the settled figure, and discard the other. Both are disclosed here precisely so a reader (or their tax professional) can go pull the current-year documents directly from groton-ct.gov and mysticfd.org and see which one is actually in effect for the bill year that matters to them.
The Practical Upshot: Same ZIP Code, Different Tax Reality
Put the two sides side by side and the gap is not trivial. Using the best same-era figures found in this research, a Stonington-side Mystic property runs roughly 19.8 combined mills, while a Groton-side Mystic property runs roughly 27.2 to 27.6 combined mills -- a difference on the order of 7 to 8 mills, which is a meaningfully different effective tax burden on a comparably valued home. Two houses facing each other across a downtown Mystic street, both carrying the identical "Mystic, CT 06355" mailing address and ZIP code, can sit under entirely different town governments, entirely different mill rates, and entirely different fire-district add-ons.
The one institution that treats Mystic as a single place regardless of which town line runs through it is the Mystic Fire District itself. Per its own 2024 Annual Report, the district covers assessed valuation of $792.5 million on the Groton side and $351.1 million on the Stonington side, operates from two stations -- the B.F. Hoxie Engine Company and the Mystic Hook & Ladder Company -- responds to roughly 800 calls a year, and carried a total proposed budget of $3,068,646, with $2,326,703 in required tax revenue and $1,942,373 allocated to fire-protection spending. The district also operates Mystic River Park through its own elected Park Commission. It is a genuinely cross-town institution in a place where almost nothing else is -- which is part of why its own rate figures are worth checking directly rather than assuming they always align neatly with either town's separate schedule.
Income Context, Heavily Hedged -- Not a Substitute for Tax Figures
Household income is sometimes used as a rough proxy for a market's overall cost profile, but the figures available for this area are too unsettled to use that way here, and this page is not going to paper over that. The Town of Groton's median household income is reported at $69,811 (2019-2023 American Community Survey 5-year estimate, via Neilsberg). For the Town of Stonington, the same source page shows two conflicting figures -- $78,366 and $98,058 -- without a clear resolution of which applies; this page presents both and resolves neither. A third figure sometimes seen for Stonington, $109,167 from DataUSA, is attached to a population base of only 934 people and is almost certainly describing a small sub-area rather than the actual 18,335-person town, so it is excluded here rather than repeated as if it were reliable.
None of these income figures should be read as a stand-in for an actual mill rate or an actual tax bill -- they describe household income, not assessed value, not mill rates, and not what a specific property will owe. They are included only as general background, and only with the caveats attached, because presenting a single clean number here would overstate how settled this data actually is.
Population Context: Three Separate Numbers That Should Never Be Blended
Three different population figures come up around this market, and mixing them together produces nonsense, so they are kept separate here. The Mystic census-designated place itself had a 2020 Census population of 4,348 -- this is the actual village most people mean when they say "Mystic." The Town of Groton, the larger municipality that governs the west bank, had a 2020 Census population of 38,411. The Town of Stonington, governing the east bank, had a 2020 Census population of 18,335, though the Connecticut Conference of Municipalities' own profile lists 18,431 -- close enough that this page presents it as roughly 18,300 to 18,400 rather than picking one figure and calling it exact.
The reason this matters for a tax page specifically is that Mystic's 4,348 residents are a small fraction of either town's total population and total grand list, and the tax rate that applies to a Mystic property is set by an entire town's budget process -- Groton's 38,411 residents or Stonington's roughly 18,300 to 18,400 -- not by anything specific to the village itself. Mystic residents have no separate vote on their own mill rate, because there is no separate Mystic government to vote for one.
Before You Rely on Any Number Here, Verify It Directly
Every specific figure on this page -- both town mill rates, both fire-district add-ons, the sewer-district figure, the grand-list valuations, the income figures -- is time-stamped to the specific fiscal year or reporting period cited, and mill rates change annually by design as towns set new budgets. This page found a real, unreconciled discrepancy between two supposedly matching numbers (the fire district's 2.206-mill Groton-side figure versus the town's 2.41-mill schedule figure) without even looking for one -- which should be read as a sign to independently verify, not as a one-time fluke.
This is not a substitute for professional advice, and it is not written to be one. Before making a purchase decision based on property tax exposure in Mystic, pull the current mill-rate schedule directly from groton-ct.gov or stonington-ct.gov depending on which side of the river the property sits on, pull the current rate sheet directly from mysticfd.org for the fire-district add-on, and consult a Connecticut-licensed tax professional or real estate attorney who can confirm the actual current bill for a specific parcel. Mill rates, fire-district assessments, and sewer-district boundaries are all subject to change on their own schedules, and only the current-year source documents -- not this page -- should be the basis for a real financial decision.
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Get a Free Agent Referral →Independent research. No ads. No sponsored listings. Mystic, CT is confirmed as an unincorporated village and census-designated place straddling the Mystic River between the Town of Groton and the Town of Stonington, with no government or budget of its own. Groton figures (24.81-mill base rate on the 2024 Grand List for FY2026 bills due July 1, 2025; 2.41-mill Mystic fire-district add-on; 2.50-mill Old Mystic fire-district add-on, not applicable here; 0.38-mill Groton Sewer District add-on) are per the Town of Groton's own mill-rate schedule. Stonington figures (18.18-mill FY2025 real/personal property rate; 2025 grand-list valuation of roughly $4,081,337,444; total tax levy of roughly $71.18 million) are per the Connecticut Conference of Municipalities' Data Hub profile. Mystic Fire District figures (1.647-mill Stonington-side rate, 1.620-mill basic rate, 2.206-mill Groton-side rate) are per the district's own 2024/2025 rate sheet; district-wide figures (assessed valuation of $792.5 million Groton-side and $351.1 million Stonington-side, roughly 800 calls per year, a $3,068,646 total proposed budget, $2,326,703 in required tax revenue, and $1,942,373 in fire-protection spending) are per the district's own 2024 Annual Report. Income figures (Groton's $69,811 median household income and Stonington's conflicting $78,366 and $98,058 figures) are per Neilsberg's citation of 2019-2023 American Community Survey 5-year estimates; a third Stonington figure of $109,167 from DataUSA is excluded because it is attached to a population base of only 934 and almost certainly does not describe the actual town. Population figures (Mystic CDP 4,348; Town of Groton 38,411; Town of Stonington 18,335) are per the 2020 Census, with the Connecticut Conference of Municipalities listing Stonington at 18,431. Governance details (Groton's council-manager structure with Town Manager John Burt and a 45-member Representative Town Meeting; Stonington's First Selectman and Board of Selectmen structure with Bill Middleton elected First Selectman on November 4, 2025, succeeding Danielle Chesebrough) are drawn from each town's own public records. This research explicitly did not find and did not invent: a single reconciled same-fiscal-year combined mill rate for either side of the river, a settled Stonington town median household income, any Mystic CDP-level income or home-value figure, or a current reconciled median home sale price for Mystic. The unresolved gap between the Mystic Fire District's reported 2.206-mill Groton-side rate and the Town of Groton's own 2.41-mill schedule figure is disclosed rather than resolved. For current mill rates and bills, consult groton-ct.gov and stonington-ct.gov directly; for current fire-district rates, consult mysticfd.org directly; for how any of this applies to a specific property or purchase, consult a Connecticut-licensed tax professional or real estate attorney.