Key Biscayne

Key Biscayne is a distinctive submarket in Miami-Dade County with a unique investor profile. Cap rates of 3.8%-4.2% and average rents of $4,200/month position this zone in the premium segment of the market. The 55% five-year appreciation reflects measured growth.

The expense side is where Key Biscayne demands close attention. Insurance costs run approximately $3,200 per unit annually, rated VERY HIGH risk due to the VE (Muy Alto) FEMA flood designation. Combined with a millage rate of 15.8 and operating expenses that typically run 38% of gross rent, investors need to model total expenses carefully to avoid overestimating net returns. Property taxes average $6,500 per unit per year in this zone.

Key Biscayne serves a population of 14,000 with a median household income of $145,000. The walkability score of 45/100 and transit score of 20/100 reflect its coastal premium character. Crime grade A+ and school rating A+ factor into tenant quality and retention. Vacancy at 3% signals tight supply.

For multifamily investors evaluating Key Biscayne in 2026, the entry point ranges from $600K to $700K per unit. Ultra-premium island. NOT a yield investment — it's wealth preservation. Astronomical insurance. Lowest cap rate in the county. UHNW only. Investors comparing this zone against the broader Miami-Dade market should weigh the 3.8%-4.2% cap rate against the county-wide range of approximately 3.8% (Key Biscayne) to 7.5% (Florida City), and factor in the significant variation in insurance and tax burden across the county's 34 investable zones.