21 William St, Ossining, NY 10562 Property Records

Westchester County and Ossining Town property record for 21 William St, Ossining, NY 10562

Property Summary

Property Type	Apartments (5+ Units)
Lot Size	0.04 acres (1,742 sqft)
Owner	2 Individual Names on Record
Last Sale	$106,001 (Jun 1997)
Tax Bill	$17,284 (2026)
Flood Zone	Zone X (minimal risk)
APN	`554203 97.07-4-83`

Property Details

APN / Parcel Number

Primary APN	`554203 97.07-4-83`
Alternative APN	`55420300318 046 010`

Interior

Units	4 Units

Exterior

Lot Area	1,742 sqft (0.04 acres)
Lot Dimensions	49 ft deep x 41 ft wide

Location & Zoning

Street Address	21 WILLIAM ST
City	OSSINING
State	NY
Zip	10562-5537
Property Category	Residential
Property Type	Residential > Multi-Unit > Apartments (5+ Units)
Legal Block	4
Legal Lot Number	83.000
Jurisdiction	WESTCHESTER NY
Township / Civil Division	OSSINING
Census Block Group	2
Census Block	2004
Census Tract	13304

Owner

Source: Westchester County and Ossining Town records, as of October 21, 2026

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

Owner of Record	2 Individual Names on Record
Mailing Address	124 GALLOWS HILL RD, CORTLANDT MANOR, NY 10567-1177
Owner Type	Individual

Deeds, Mortgages & Sale History

Assessor's Deed Record

Deed Names	2 Names on Deed
Last Sale	Jun 24, 1997 · Amount on Record
Deed Sale	Jun 24, 1997 · Amount on Record
Deed Book / Page	11750 / 316
Record Updated	Oct 29, 2026

Tax Assessment & Valuation

Source: Westchester County and Ossining Town assessment roll, as of May 14, 2026

Property Jurisdictions

Type	Name
State	New York
County	Westchester County
County Subdivision	Ossining Town
Municipality	Ossining Village
Unified School District	Ossining Union Free School District (PK - 12)

Tax Bill & Assessment History

Year	Tax Bill	Assessed Value	Assessed Market Value
2026	$17,284.00 (+50.69%)
2025	$11,470.00	$538,200 (+1.49%) Land $170,000 Building $368,200	$538,200 (+1.49%) Land $170,000 Building $368,200
2024		$530,300 (+2.95%) Land $170,000 Building $360,300	$530,300 (+2.95%) Land $170,000 Building $360,300
2023		$515,100 Land $170,000 Building $345,100	$515,100 Land $170,000 Building $345,100

Assessed value and assessed market value are set for property tax purposes and are not market price estimates.

Flood

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

FEMA Flood Zone	Zone X minimal risk
Flood Insurance Requirement	Not required lenders may require it
Nearby Flood Policies	1 in force
Nearby Flood Claims	2 (2009–2021)
Claims Outside the SFHA	2 of 2
Most Recent Claim	Sep 2021 · Remnants Of Hurricane Ida

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 Risk	Not 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 System	OSSINING WATER DEPARTMENT serves 30,000 people · EPA ID NY5903451
Water Source	Surface water
Last State Inspection	Jul 2025
Lead	3 ppb (2025) action level 15 ppb

Violations Reported to EPA

Water Quality	None last 10 years
Treatment and Procedure	None last 10 years
Monitoring and Reporting	None 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 616 locations within half a mile, as of December 31, 2025

Provider	Max Down / Up (Mbps)
Optimum Fiber · Cable	8,000 / 8,000
Verizon Fiber · Fixed Wireless in parts of the area	2,300 / 2,300