21 Walnut St
Islip, NY 11751
3 bd 1 ba Built 1965 Lot 19,602 sqft single_family
No recorded sales
Location
Timeline: Sale, Listing & Tax History
Recorded events
No recorded events
No sale or listing events are on file for this property.
Tax assessment history
| Year | Building | Land | Total assessed | Tax paid |
|---|---|---|---|---|
| 2025 | $22,850 | $11,800 | $34,650 | $14,723 |
| 2017 | $22,850 | $11,800 | $34,650 | $6,946 |
| 2016 | $22,850 | $11,800 | $34,650 | $6,959 |
| 2015 | $22,850 | $11,800 | $34,650 | $7,000 |
| 2014 | $22,850 | $11,800 | $34,650 | $6,914 |
| 2013 | $22,850 | $11,800 | $34,650 | $6,880 |
| 2012 | $22,850 | $11,800 | $34,650 | $6,623 |
| 2011 | $22,850 | $11,800 | $34,650 | $6,333 |
| 2010 | $22,850 | $11,800 | $34,650 | $6,050 |
| 2008 | $22,850 | $11,800 | $34,650 | $6,784 |
| 2007 | $22,850 | $11,800 | $34,650 | $6,249 |
Property facts
Year built
1965
Property type
single_family
Stories
3
Beds
3
Baths
1
Living area
—
Lot size
19,602 sqft
ZIP code
11751
City
Islip
Street
Walnut St
Coordinates
40.74596, -73.20640
Block-level micro-comps
Same street, ±3 house numbers, sold in the last 24 monthsFrequently asked questions
When did 21 Walnut St last sell?
No public-record sale is on file for 21 Walnut St.
What is the current tax assessment for 21 Walnut St?
The most recent total assessment for 21 Walnut St (year 2025) is $34,650 with $14,723 in property tax.
When was 21 Walnut St built?
21 Walnut St was built in 1965.
How does 21 Walnut St compare to others on Walnut St?
We track 7 other properties on Walnut St. Browse the list under "Other properties on Walnut St" to compare beds, baths, and sale history.
What are the property facts for 21 Walnut St?
21 Walnut St is a 3 bed, 1 bath, 19,602 sqft lot single_family.
Is 21 Walnut St a flip candidate?
No — 21 Walnut St does not appear in our flips dataset.
Is 21 Walnut St a tax-appeal candidate?
No — 21 Walnut St is not currently flagged as a tax-appeal candidate.
Forecast for this area
ZIP-area linear projection — not a per-property automated valuationQuarterly trend
+1.3%
Implied 1-yr
+5.1%
2026 Q1
$500.4K
2026 Q2
$506.3K
ZIP 11751 — Median Price History + Forecast
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