Every Nantucket homeowner gets a number from the town assessor. This year, sellers are clearing far above it—and that gap is worth understanding whether you're buying, selling, or just curious what your place is really worth.
Two numbers, one house
The assessed value is what the Town of Nantucket uses to calculate your property tax. Market value is what a buyer will actually pay. On most of the mainland, those two numbers live within shouting distance of each other. On Nantucket, they don't.
Through the first half of 2026, island homes sold at 148.40% of their assessed value—call it roughly a dollar-fifty of market price for every dollar the town has on the books. In June alone, the twenty homes that traded closed at 167.20% of assessed value. (Source: LINK Nantucket, Year-To-Date Sales Summary and Sales History for June 2026.)
That is not a rounding error. It's a structural feature of this market, and it catches people off guard in both directions.
The backdrop: fewer sales, firmer prices
It helps to know what kind of market this gap sits inside. Through the first six months of 2026, 111 properties of all types changed hands island-wide, down from 148 in the same stretch a year earlier. Yet the median home price rose to $3,675,000, up about 11% year over year. (Source: LINK Nantucket, Year-To-Date Sales Summary, 2026.) Fewer trades, firmer prices—that's a market where value is holding, which is exactly the environment where a stale assessment falls furthest behind.
Why the gap exists
A few reasons, none of them mysterious.
Assessments lag. The town sets values on a schedule, using sales data that's already a year or more old by the time your bill arrives. In a market that has moved as fast as Nantucket's, last cycle's number is stale before the ink dries.
Land does the heavy lifting here. On an island where a buildable lot is the scarce thing, much of a property's real value sits in the dirt, not the drywall—and land is the hardest piece to assess precisely. When an older house on a good lot is taken down and rebuilt, the market reprices it long before the assessor catches up.
The extreme cases make the point. In June, 10 Rudder Lane in Miacomet sold for $4,150,000 against an assessed value of $985,501—421% of assessed. That's the signature of new construction on a lot the town still had on the books at its old, pre-build number. (Source: LINK Nantucket, Sales History for June 2026.)
What it means if you're buying
Don't anchor to the assessment. I see buyers pull up a property record, spot a number a fraction of the asking price, and assume they've found either a steal or a scam. Usually it's neither. The assessed value tells you what the town will tax, not what the house will sell for.
A better reference point is what comparable homes have actually closed at recently. Through June, island homes sold at 94.58% of their asking price—real, but disciplined, negotiation. The assessment won't tell you where a given deal lands. The comps will. When 44 Sankaty Road in 'Sconset closed at $4,212,500 this June, it went for 142% of its assessed value; a buyer working off the assessor's figure would have been badly out of position. (Source: LINK Nantucket, Sales History for June 2026.)
What it means if you're selling
The flip side is just as important. Your assessment is not a ceiling. If a neighbor's place is on the books at $2 million, that has almost nothing to do with what yours will bring in today's market. Pricing off the assessor's figure—high or low—is one of the more common ways sellers either leave money on the table or scare buyers off with a number that doesn't match the house.
It cuts the other way too, in your favor: because assessments run well below market, a Nantucket property-tax bill can look almost gentle relative to the purchase price. That's worth understanding before you buy, and I wrote about the full cost of ownership in the Kalman Co. guide to Nantucket property taxes and closing costs.
Myths I keep hearing about the Nantucket market
The assessment gap is one example of a story people repeat about this island that the data doesn’t back up. Here are four more I field every week, each checked against LINK’s current reports.
Myth: There’s plenty to choose from right now.
Fact: Nantucket ended June with 167 properties on the market, down 32% from 245 a year earlier, and LINK puts residential absorption at 10 months of inventory. (Source: LINK Nantucket, Inventory Activity and Market Snapshot, June 2026.) What this means: when the right house shows up, you’ll know it—you’ve already seen everything else. Keep your short list and your financing ready before you need them.
Myth: Prices are coming down.
Fact: The median Nantucket home sold for $3,675,000 in the first half of 2026, up 11.36% from the same stretch last year, and sellers collected 94.58% of asking on average. (Source: LINK Nantucket, Year-To-Date Sales Summary, July 1, 2026.) What this means: waiting for the island to go on sale isn’t a strategy. Buying the right house well is.
Myth: Summer floods the market with new listings.
Fact: June brought 52 new listings, down from 68 last June, and only 16 sellers adjusted their price—half as many as a year ago. (Source: LINK Nantucket, Inventory Activity, June 2026.) What this means: sellers don’t blink in July. The real negotiating season opens after Labor Day, so use August to do your homework.
Myth: Homes here sit on the market for months.
Fact: The well-priced ones don’t. In June, 15 Kendrick Street found its buyer in 4 days at full ask, 20 Rudder Lane in 6 days at full ask, and 5 Rudder Lane in 3 days at 102% of asking—while the month’s biggest sale, 9 Pleasant Street, took 373 days and closed at 87.76% of ask. (Source: LINK Nantucket, June 2026 sales history and listing records.) What this means: days on market isn’t weather, it’s pricing. Price to the comps and this island moves in days; price to ambition and you’re still on the market at Thanksgiving.
The one-line version
On Nantucket, the assessed value is a tax figure, not a market figure—and in 2026 the two are running roughly a third to a half apart. Treat the town's number as the starting line for a tax bill, and treat recent, comparable sales as the real guide to value.
If you want to know where your specific home, or a place you've been watching, actually sits—not the assessment, the real number—I'm glad to run the comps and walk you through it. No pressure, no obligation. sean@thekalmanco.com.