The Islands Have the Highest Limit and the Least Use for It
Program and regulatory figures verified September 25, 2026. Details change; confirm your scenario with us.
Massachusetts gives the islands its highest conforming limit and the islands have outgrown it by $308,566. Plan an island move-up as a jumbo file from the start.
The median is already jumbo
Dukes and Nantucket counties carry $1,249,125, the highest one-unit conforming limit in Massachusetts. Vineyard Haven's typical home value in August 2026 was $1,557,691.
The typical home is $308,566 past the ceiling. This is not a market approaching a threshold, like Ocean City in New Jersey or Cape Cod across the Sound. It cleared it some time ago and is still rising, at 5.1% year over year.
So the useful planning assumption for an island move-up is that you are on investor guidelines from the start rather than hoping to stay agency.
What that changes
Inside agency financing the departing-residence rules are published. Fannie Mae B3-3.8-05, dated 09/02/2026, sets the offset at gross rent times 75% less that property's PITIA, bars leases as income documentation, and requires six months of reserves on the vacated home under 12 months of property management experience.
Above the conforming limit each investor sets its own. Three patterns recur:
- Deeper reserves, with the departing residence adding its own requirement on top.
- Tighter treatment of the departing payment. Some investors will not remove it until the sale funds, regardless of contract status.
- More documentation of the exit, meaning how and when the departing home is expected to sell gets underwritten rather than assumed.
That third one is where island files differ most from mainland ones. A seasonal market with a narrow selling window is exactly the fact pattern an investor will want documented. Carrying both payments with a later recast is often the more dependable structure. See the structures page.
And the gains here are the largest
Island properties held for decades carry the biggest accumulated gains in the state, which puts the Massachusetts surtax question squarely in play. mass.gov sets the 2026 threshold at income exceeding $1,107,750, with an additional 4% above it, and a gain above the federal exclusion flows into that year's taxable income.
Take it to your CPA before you sequence the move, not after. See the surtax page, the net proceeds page and the Cape Cod page.
Frequently asked questions
What is the conforming loan limit on Martha's Vineyard and Nantucket?
$1,249,125 on one unit for 2026 in both Dukes and Nantucket counties, the highest in Massachusetts. Each island is its own metropolitan area.
Is a typical Martha's Vineyard purchase a jumbo loan?
Yes. Vineyard Haven's typical home value was $1,557,691 in August 2026, which is $308,566 above the $1,249,125 limit that applies there, so the median purchase exceeds the highest conforming limit in the state.
What changes when an island move-up is a jumbo file?
The departing-residence rules stop being the published agency ones in Fannie Mae B3-3.8-05 and become the investor's own. That usually means deeper reserves, more documentation of how the departing home will sell, and with some investors no removal of the departing payment until the sale funds.
Mike Certo · NMLS #260555 · Cornerstone First Mortgage NMLS #173855 · Equal Housing Lender. Educational content about financing, not a loan commitment and not legal, tax, or real estate advice. The Massachusetts surtax threshold is set by the Commonwealth and indexed annually, and whether a home sale reaches it depends entirely on your facts; your CPA, your closing attorney, and your real estate agent each handle their own part. Loans are subject to borrower and property qualification.