669 S Mashta Dr, Key Biscayne FL 33149, KEY BISCAYNE, FL, 33149
Active60 days on marketListed Jun 5, 2026MLS #A12033340
About this home
669 S Mashta Dr, Key Biscayne FL 33149
Located on the exclusive and highly sought-after Mashta Island, this exceptional property offers a rare opportunity to build your dream home or enjoy the existing beautifully refurbished residence. The home features new bathrooms, updated flooring, and tasteful modern finishes throughout. Designed for relaxed Florida living, the spacious covered terrace overlooks a stunning mosaic-tiled pool, creating the perfect setting for entertaining or enjoying the tropical surroundings. A unique opportunity in one of Key Biscayne's most desirable neighborhoods. Easy to show.
Facts & features
The home at a glance
4
Bedrooms
3.5
Bathrooms
3,382
Sqft
1960
Year built
$1,715
Per sqft
Inside
Outside & construction
Community & fees
Utilities & systems
The numbers
What it really costs
Built from this home's actual numbers — the most recent property-tax bill on record — not generic estimates.
$35,460 /mo · 10% down Conventional, 30-yr fixed at 6%
The assumptions
Above the FHA loan limit for our service areas, so Conventional is the default. VA buyers: switch below — $0 down.
These numbers assume a generic buyer — your credit, down payment and loan program change them. Get the real quote in minutes:
Andrew Acosta
Acosta Home Loans with PRMG · NMLS #1468866
Run your own numbers
FHA isn’t available at this price — the loan would exceed the $541,287 FHA limit for our service areas.
Estimated payment
$35,460/mo
Includes estimated PMI — it drops off once you reach 20% equity. Taxes reflect the most recent bill on record; insurance is a typical-Florida estimate. Your lender’s numbers will differ. CENTURY 21 Edge partners with Florida’s best lenders.
Value check
Is the price right?
The internet’s favorite home-value number comes from a single automated model that has never seen the street, the finishes, or the view — which is why it routinely misses by tens of thousands of dollars. The edgeAI estimate combines multiple independent data sources with our team’s on-the-ground expertise in this exact market.
vs edgeAI estimate
+120.3%
$/sqft vs Key Biscayne actives
$1,715 vs $1,203
Days on market
60 vs 62 typical
Where $1,715/sqft sits among the 134 Key Biscayne actives
The edgeAI estimate is a starting point, not an appraisal or a broker price opinion. It is generated from public records, listing data and market modeling, and is subject to change once a licensed real estate professional personally inspects the property. Condition, floor, view and lot are not fully captured by any model — ask us for a full comparative market analysis.
Where it sits
Inside Village Of Key Biscayne
Get to know Key Biscayne. See the full Key Biscayne guide →
Village Of Key Biscayne — neighborhood snapshot
Population
14,603
Median age
44
Median income
$152,910
Median home value
$1,246,268
Avg household
3
Households w/ children
2,233
For the school run
Dade County School District
School assignments and ratings via edgeAI — always verify with the district.
The numbers that matter
The Key Biscayne market
$1.6M → $1.6M
Key Biscayne median sold, yr/yr
94.9%
Sale-to-list ratio (12 mo)
6 of 134
Key Biscayne actives have cut their price
This home is listed 22204% above the KEY BISCAYNE 33149 median. See the full Key Biscayne market guide →
Paper trail
This home's history
Reality check
What actually sold near 669 S Mashta Dr
Asking prices are opinions — closed sales are facts. The most comparable homes that actually changed hands nearby in the last twelve months.
Sold · Feb ’26$4,750,000
669 S Mashta Dr, Key Biscayne FL 33149 · same community
3 bd · 3.5 ba · 3,382 sqft · $1,404/sqft · 38 DOM
Sold · Apr ’26$3,625,000
765 Crandon Blvd # 102, Key Biscayne FL 33149
4 bd · 4.5 ba · 3,368 sqft · $1,076/sqft · 127 DOM
Sold · Aug ’25$6,400,000
Nearby listing
4 bd · 5.5 ba · 3,581 sqft · $1,787/sqft
Closed-sale data from the MLS, last 12 months, selected for similarity in size and location. No two homes are identical — ask us for a full comparative analysis.
Your home team
The pros in your corner
Buying a home is two conversations — the home and the money. Here’s who handles each, side by side, already working together.
Your agent
Kat Bonelli
REALTOR® · CENTURY 21 Edge
Tours, negotiation, and every question about 669 S Mashta Dr — start here.
Your lender
Andrew Acosta
Acosta Home Loans with PRMG · NMLS #1468866
Pre-approval, rates, and the real monthly number for 669 S Mashta Dr — before you fall in love.
See it in person
Schedule a tour
Pick a day that works — this goes straight to Kat's phone and CRM.
Straight answers
669 S Mashta Dr FAQs
What would the monthly payment be for 669 S Mashta Dr, Key Biscayne FL 33149?+
With 10% down on a 30-year Conventional loan at 6%, the all-in payment lands around $35,460/mo — principal and interest, the actual property-tax bill and typical Florida insurance. The payment calculator on this page lets you switch loan type (FHA, Conventional, VA) and adjust the down payment, rate and term.
What are the property taxes on 669 S Mashta Dr, Key Biscayne FL 33149?+
The most recent tax bill on record (2025) was $22,013. A new owner's bill can differ once the sale price resets the assessed value — we can walk you through what to expect.
How does the price compare to other homes in Key Biscayne?+
At $5,799,000, this home is listed about 109% above the Key Biscayne median of $2,775,000. The market section on this page shows how the area is trending.
Which schools are assigned to 669 S Mashta Dr, Key Biscayne FL 33149?+
Key Biscayne K-8 Center (elementary), District Instructional Center (Dic) (), Coral Gables Senior High School (high), Ponce De Leon Middle School (middle), Instructional Center System Wide (), Title I Migrant Education Program () — Dade County School District. Always verify school assignments with the district before relying on them.
Keep looking
Similar homes nearby
Listing courtesy of Coldwell Banker Realty · Maureen Jauregui. MLS #A12033340.
IDX information is provided exclusively for consumers’ personal, non-commercial use and may not be used for any purpose other than to identify prospective properties consumers may be interested in purchasing. Data is deemed reliable but is not guaranteed accurate by Miami Association of REALTORS®.
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