Key Biscayne

• It is an island village, not a Miami neighbourhood. Key Biscayne is its own incorporated municipality with its own council, police and fire departments, reached from the mainland by a single tolled road — the Rickenbacker Causeway.
• The typical home is worth $1,706,575, up 2.6% over the past year (Zillow Home Value Index, 30 June 2026). The median sale price was $1,583,333 as of 31 May 2026, against a median list price of $1,711,667 at 30 June 2026.
• It is slow, and that is the point. Median days to pending is 58; one listings source puts median days on market at 73 with 169 active listings. Few units trade in any given month, so a single closing moves the averages.
• Roughly a third of the island is parkland. Crandon Park sits at the north end, Bill Baggs Cape Florida State Park at the south. Neither will ever be developed, which caps supply permanently.
• The zoned public schools are Key Biscayne K-8 Center on the island and Coral Gables Senior High about eleven miles away. MAST Academy on Virginia Key admits by lottery, with priority for Village residents on two tracks.

What Key Biscayne actually costs in 2026

The honest answer is that Key Biscayne has two price tables and they barely overlap.

The Zillow Home Value Index for Key Biscayne stood at $1,706,575 on 30 June 2026, up 2.6% year over year, with a median sale price of $1,583,333 recorded through 31 May 2026 and a median list price of $1,711,667 at the end of June. That is the index view — a modelled typical value across the whole housing stock, condos included.

The listings view is different. Movoto’s June 2026 read put the median at $2,350,000 and $1,149 per square foot across 169 active listings, with a median 73 days on market.

Both numbers are correct, and the gap between them is the most useful thing on this page. The index is weighted toward the island’s large inventory of older mid-rise condominiums. The listings median is weighted toward what is currently for sale, which skews to single-family houses and waterfront. If you are buying a house on the water here, the $1.7 million figure will mislead you badly. If you are buying a two-bedroom in a 1970s building on Crandon Boulevard, the $2.35 million figure will.

Ask which table you are shopping from before you anchor on a number.

Why supply here can never really increase

Key Biscayne is a barrier island of a few square miles, and a large share of it is permanently protected. Bill Baggs Cape Florida State Park occupies the southern tip, including the Cape Florida Lighthouse — the oldest standing structure in Greater Miami. Crandon Park, county-owned, occupies much of the north. Between them sits the Village.

What that means practically: there is no meaningful development pipeline. New supply arrives as a teardown-and-rebuild on an existing lot, or as a resale. That is unlike almost every other market covered on this site — compare it with Brickell, where the skyline changes every eighteen months, or Miami’s pre-construction pipeline generally.

Constrained supply is why the island holds value through soft patches. It is also why patient buyers do better here than aggressive ones: there is rarely a second identical unit to move to.

The parts of the island, and how they differ

Buyers tend to arrive thinking of Key Biscayne as one place. It functions as several.

• Mashta Island — a small enclave at the island’s southwest, reached by its own bridge. Almost entirely single-family, much of it on deep water with direct bay access. This is the top of the market.
• Matheson Estates — established single-family streets, generous lots, mature canopy. Less water frontage than Mashta, more house for the money.
• Smugglers Cove — waterfront and canal-front houses on the bay side, historically favoured by boat owners for the protected dockage.
• Crandon Boulevard and the ocean side — where nearly all the condominium stock sits, from 1960s and 1970s mid-rises through to the newer luxury buildings and the residences associated with The Ritz-Carlton Key Biscayne.
• The Village core — walkable, low-rise, and the reason many families choose the island: groceries, restaurants, the K-8 school and the community centre are all inside a few blocks.

If dockage is the priority rather than the address, it is worth reading the Miami waterfront homes guide alongside this page — bridge height, channel depth and slip width decide more waterfront purchases than square footage does.

Every condominium on Key Biscayne

The island has a small, closed set of condominium buildings and no realistic path to more. That scarcity is the whole investment case.

What to check before you buy a Key Biscayne condo

The island’s condominium stock is old by Miami standards, and Florida’s post-Surfside regime falls hardest on exactly that profile. Before you write an offer on any building here:

• Milestone inspection status. Buildings three storeys and above face a structural milestone inspection at 30 years — sooner near the coast. Ask for the report, not a summary of it.
• The Structural Integrity Reserve Study, and whether the association is funding it. Associations that had waived reserves were required to begin funding them from 1 January 2026. A board still keeping contributions artificially low is deferring a cost onto your resale price, not saving you money.
• Whether the building is warrantable. Fannie Mae and Freddie Mac maintain a non-public list of condominium projects they will not lend against, and the South Florida count has roughly doubled in two years. Limited Review — the shortcut that let a lender approve a unit without fully assessing the building — was eliminated on 3 August 2026, so more buildings now face full scrutiny. Units in ineligible buildings routinely trade 15% to 30% below comparable units in eligible ones. The full explanation is on the Miami condos for sale page.
• Insurance, honestly quoted. This is a barrier island. Get a real windstorm and flood quote on the specific unit before you are emotionally committed, not after.

None of this should scare you off the island. It should change the order in which you do things.

Living here — the trade-off nobody spells out

Key Biscayne is one of the few places in Miami-Dade where children ride bicycles to school and parents let them. It has beaches without the South Beach crowd, a marina, tennis at Crandon, and a village centre you can walk end to end. Brickell, Coral Gables and Coconut Grove are a short drive away.

The trade-off is the causeway. It is the only road on and off the island, it is tolled, and it is the single variable that decides whether island life suits you. Residents buy an annual plan — the renewal window runs each summer through 30 September — and resident rates have been the subject of significant proposed increases in recent county budget cycles. If you commute daily to Downtown or Brickell, drive it at 8am on a Tuesday before you fall in love with a house. If you work from home or your commute is occasional, the causeway is a moat, and the moat is the amenity.

Hurricane access is the other half of that conversation. The island evacuates early and reopens late. Ask any long-term resident; they will tell you plainly.

Who buys on Key Biscayne

Three groups, consistently. Families who want a walkable, low-crime island with a school on it and are willing to pay for that specific combination. Latin American buyers — the island has a long-established South American community and a genuinely bilingual civic life. And boat owners, for whom the bay-side dockage and the run to Stiltsville and the flats are the whole proposition.

It is not a good fit for a buyer who wants nightlife on the doorstep, a brand-new tower with a full amenity deck, or the ability to sell quickly in a soft market. Inventory turns slowly in both directions.

How I would approach it

If you are looking on Key Biscayne, the useful work is not scrolling listings. It is deciding, early, whether you are buying land or buying a building — because the two markets behave differently, price differently, and carry completely different risk.

I have been selling Miami real estate since 2002 and have closed more than a billion dollars in property. Tell me what you are actually trying to do and I will tell you plainly whether the island fits, and which three streets or buildings are worth your weekend.

Get in touch, or read more about how I work. If Key Biscayne turns out not to be it, the Miami neighbourhoods map is the fastest way to narrow the alternatives.

Sources

• Zillow — Key Biscayne, FL housing market, data through 30 June 2026.
• Movoto — Key Biscayne, FL market trends, June 2026 data, page updated 20 July 2026.
• Village of Key Biscayne — Our Schools.