15 Riverside Avenue, Mastic Beach, NY 11951

$699,999 · 4 bed · 3 bath · 2,364 sq ft · built 1988 · MLS# 1059003 · Active

Breathtaking waterfront views and peaceful sunsets set the stage for this updated 4 Bedroom, 2.5 Bath Hi-Ranch on Poospatuck Creek, with direct access to the bay. The first level features updated flooring, Led lighting, summer kitchen, spacious living room, bedroom, ample storage and sliders to the deck- an ideal setup for mom, returning children, or guests Upstairs, Cathedral ceilings and hardwood floors create a bright and open feel. This Main level offers two generously sized bedrooms, and a spacious primary with walk in closet and half bath.The remodeled kitchen features…

Single-family homes in the William Floyd Union Free School District sold for a median of $510,000 (typically $430,000–$580,000) across 494 recorded sales between Oct 6, 2025 and Oct 2, 2026, up 5.2% on the 12 months before. This home's $699,999 list price sits in the luxury single-family tier for the William Floyd Union Free School District.

ZIP 11951 has about 5.6 months of single family inventory — balanced market. Supply and demand are roughly even, so buyers and sellers share leverage with fair, predictable pricing.

At about $8,497 a year, this home's property tax is in line with the roughly $8,000 typical for William Floyd Union Free School District. Suffolk bills combine town, school and special-district levies, so two homes at the same price in neighboring districts can carry materially different taxes. Exemptions such as STAR, Senior or Veteran move the number as well — a new owner's bill is often not the same as the seller's.

OneKey MLS (recorded LI sales, trailing 12mo) + actual tax