18 William Ave, East Islip, NY 11730 Property Records

Suffolk County and Islip Town property record for 18 William Ave, East Islip, NY 11730

Property Summary

Property TypeSingle Family Home
Lot Size0.49 acres (21,344 sqft)
Owner2 Individual Names on Record
Last Sale$355,000 (Mar 2014)
Tax Bill$16,369 (2024)
Deeds & MortgagesJan 2019 Refinance
Flood ZoneZone X (minimal risk)
APN472889 372.-4-16.1

Property Details

APN / Parcel Number

Primary APN472889 372.-4-16.1
Alternative APNs
  • 0500-372.00-04.00-016.001
  • 0500372000400015000
  • 472800771760

Exterior

Lot Area21,344 sqft (0.49 acres)
Lot Dimensions151 ft deep x 144 ft wide

Location & Zoning

Street Address18 WILLIAM AVE
CityEAST ISLIP
StateNY
Zip11730-2305
Property CategoryResidential
Property TypeResidential > Single Family > Home
Local Zoning CodeA
Legal Block2000
Legal Lot Number400
JurisdictionSUFFOLK NY
Township / Civil DivisionISLIP
Census Block Group1
Census Block1001
Census Tract147504

Owner

Source: Suffolk County and Islip Town records, as of August 11, 2026

Owner names and exact recorded amounts shown locked on this page are available instantly with a free trial.

Owner of Record2 Individual Names on Record
Mailing Address18 WILLIAM AVE, EAST ISLIP, NY 11730-2305
OccupancyOwner Occupied
Owner TypeIndividual

Deeds, Mortgages & Sale History

Assessor's Deed Record

Deed Names2 Names on Deed
Last SaleMar 18, 2014 · Amount on Record
Deed SaleMar 18, 2014 · Amount on Record
Deed Book / Page12767 / 330
Record UpdatedSep 20, 2026

January 2019: Deed of Trust, Mortgage

Document TypeDeed of Trust
JurisdictionSUFFOLK NY
Property Address18 WILLIAM AVE, EAST ISLIP, NY 11730-2305
Transaction TypeMortgage
Record UpdatedFeb 5, 2021

Transferred To (Grantee/Buyer)

NameVerified Name

Mortgage

Document Number0229950049
DateJan 9, 2019
Book Page22995/49
Lender
NameBANK OF AMERICA NA
TypeBank
Agreement
TypeStand-Alone Refinance
AmountAmount Recorded
Term337 Months
DueFeb 1, 2047

Tax Assessment & Valuation

Source: Suffolk County and Islip Town assessment roll, as of August 11, 2026

Property Jurisdictions

TypeName
StateNew York
CountySuffolk County
County SubdivisionIslip Town
Unified School DistrictEast Islip Union Free School District (PK - 12)

Tax Bill & Assessment History

YearTax BillAssessed ValueAssessed Market Value
2025$59,500 (-) Land $14,900 Building $44,600$838,028 (-) Land $209,859 Building $628,169
2024$16,369.00$838,028 (+2.54%) Land $209,859 Building $628,169
2023$59,500 Land $14,900 Building $44,600$817,307 Land $204,670 Building $612,637

Assessed value and assessed market value are set for property tax purposes, not market price estimates; both are a fraction of this property's market value.

Flood

Source: FEMA National Flood Hazard Layer, effective September 18, 2026 · OpenFEMA NFIP redacted claims and policies, as of September 2026

FEMA Flood ZoneZone X
minimal risk
Flood Insurance RequirementNot required
lenders may require it
Flood Insurance CostPremium on Record
median of 14 policies
Nearby Flood Policies14 in force
Nearby Flood Claims1 (2005)
Claims Outside the SFHA1 of 1
Most Recent ClaimOct 2005 · rainfall accumulation

Values are read at the parcel center point; flood claims are located to the census block group, not this parcel; lenders make the official flood determination.

Wildfire

Source: USDA Forest Service Wildfire Risk to Communities (2nd edition), as of 2024

Wildfire RiskNot rated
no burnable land within ember reach

Values cover an area roughly 900 ft across, not the parcel itself; insurers use their own ratings.

Drinking Water

Source: EPA Safe Drinking Water Information System, as of September 2026

Water SystemSUFFOLK COUNTY WATER AUTHORITY
serves 1,100,000 people · EPA ID NY5110526
Water SourceGroundwater
Last State InspectionJan 2024
Lead1 ppb (2025–2027)
action level 15 ppb

Violations Reported to EPA

Water QualityAsbestos
resolved · Jul 2020
Treatment and ProcedureNone
last 10 years
Monitoring and ReportingNone
last 3 years

Results are for the whole water system, not water tested at this address; lead at the tap also depends on the building's own pipes.

Internet Providers

Source: FCC Broadband Data Collection, based on 274 locations within half a mile, as of December 31, 2025

ProviderMax Down / Up (Mbps)
Optimum
Fiber · Cable
8,000 / 8,000
Verizon
Fiber
2,300 / 2,300
T-Mobile
Fixed Wireless
100 / 20

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