21 Mill St, Dorchester, MA 02122 Property Records

Suffolk County and Boston City property record for 21 Mill St, Dorchester, MA 02122

Property Summary

Property Type	Duplex
Details	8 bd · 5.5 ba · 5,043 sqft · built 1845
Lot Size	0.58 acres (25,267 sqft)
Owner	Individual Name on File
Last Sale	$1,275,000 (Dec 2015)
Tax Bill	$19,269 (2025)
Deeds & Mortgages	Mar 2024 Refinance Apr 2024 Refinance
Flood Zone	Zone X (minimal risk)
APN	`DORC W:16 P:00086 S:030`

Property Details

APN / Parcel Number

Primary APN	`DORC W:16 P:00086 S:030`

Interior

Bedrooms	8 Beds
Full Baths	5.5 Baths
Half Baths	3 Half Baths
Total Rooms	16 Rooms
Units	2 Units
Stories	3 Stories
Building Area	5,043 sqft Living Area
Gross Area	9,252 sqft
Fireplaces	1 Fireplace
Fireplace	Fireplace

Exterior

Year Built	Built 1845
Effective Year Built	Effective 2001
Architectural Style	Conventional
Exterior Material	Wood Siding
Roof Type	Gable
Roof Material	Asphalt
Lot Area	25,267 sqft (0.58 acres)
Parking Spaces	6 Parking Spaces

Utilities, Heating & Cooling

Cooling System	HVAC
Heating System	Forced Air with A/C

Location & Zoning

Street Address	21 MILL ST
City	DORCHESTER
State	MA
Zip	02122-3560
Property Category	Residential
Property Type	Residential > Multi-Unit > Duplex
Local Zoning Code	R2
Legal Subdivision	MILL POINTE
Jurisdiction	BOSTON MA
Township / Civil Division	BOSTON
Census Block Group	3
Census Block	3014
Census Tract	92101

Historic Designation

Source: NPS National Register of Historic Places, as of August 1, 2026

Historic District	Within the Harrison Square Historic District listed 2002 · 141 contributing resources · NRIS 02001190

Federal listing alone does not restrict alterations; local historic district rules, which this data does not cover, may apply.

Owner

21 Mill St, a duplex, is owned by an individual who bought it in December 2015.

Source: Suffolk County and Boston City records, as of April 14, 2026

Owner of Record	Individual Name on File
Mailing Address	16 DAWSON ST, DORCHESTER CENTER, MA 02124-2610
Owner Type	Individual

Owner names and exact recorded amounts are on file and can be viewed instantly on this page with a free 10-day trial.

Deeds, Mortgages & Sale History

Date	Document
Mar 11, 2024	Deed of Trust, Mortgage · Stand-Alone Refinance LOWELL COMMUNITY LOAN FUND INC
Apr 3, 2024	Deed of Trust, Mortgage · Stand-Alone Refinance BOSTON CITY OF

Assessor's Deed Record

Deed Names	Name on Deed
Last Sale	Dec 24, 2015 · Amount on File
Deed Sale	Dec 24, 2015 · Amount on File
Prior Sale	Jun 11, 2004 · Amount on File
Deed Book / Page	55519 / 77
Transfer Doc	0000116015
Record Updated	Oct 29, 2026

March 2024: Deed of Trust, Mortgage

Document Type	Deed of Trust
Jurisdiction	BOSTON MA
Property Address	21 MILL ST, DORCHESTER, MA 02122-3560
Transaction Type	Mortgage
Record Updated	Apr 3, 2026

Transferred To (Grantee/Buyer)

Name	Verified Name

Mortgage

Document Number	069957-291
Date	Mar 11, 2024
Book Page	69957/291
Instrument	14456

Lender

Name	LOWELL COMMUNITY LOAN FUND INC

Agreement

Type	Stand-Alone Refinance
Amount	Amount on Record

April 2024: Deed of Trust, Mortgage

Document Type	Deed of Trust
Jurisdiction	BOSTON MA
Property Address	21 MILL ST, DORCHESTER, MA 02122-3560
Transaction Type	Mortgage
Record Updated	Apr 3, 2026

Transferred To (Grantee/Buyer)

Name	Verified Name

Mortgage

Document Number	070035-141
Date	Apr 3, 2024
Book Page	70035/141
Instrument	19608

Lender

Name	BOSTON CITY OF

Agreement

Type	Stand-Alone Refinance
Amount	Amount on Record

Tax Assessment & Valuation

The 2025 property tax bill for 21 Mill St was $19,269, up 1.4% from the year before.

Source: Suffolk County and Boston City assessment roll, as of April 14, 2026

Property Jurisdictions

Type	Name
State	Massachusetts
County	Suffolk County
Municipality	Boston City
Unified School District	Boston School District (PK - 12)

Tax Bill & Assessment History

Year	Tax Bill	Assessed Value
2025	$19,269.00 (+1.42%)	$1,664,000 (-4.54%) Land $551,600 Building $1,112,400
2024	$19,000.00 (+1.49%)	$1,743,100 (-) Land $656,900 Building $1,086,200
2023	$18,721.00	$1,743,100 Land $656,900 Building $1,086,200

Assessed value is set for property tax purposes and is not a market price estimate.

Flood

FEMA maps place 21 Mill St in Zone X, an area of minimal flood risk, though there have been 1 flood claim nearby since 2000.

Source: FEMA National Flood Hazard Layer, effective January 21, 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
Community Rating System	Class 10 (0% premium discount)
Nearby Flood Policies	1 in force
Nearby Flood Claims	1 (2000)
Most Recent Claim	Aug 2000 · 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

The area around 21 Mill St has no burnable land within ember reach, so its wildfire risk is not rated.

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	BOSTON WATER AND SEWER COMMISSION (MWRA) serves 675,647 people · EPA ID MA3035000
Water Source	Purchased surface water from MWRA
Last State Inspection	Mar 2026
Lead	6 ppb (2026) action level 15 ppb

Violations Reported to EPA

Water Quality	None last 10 years
Treatment and Procedure	Lead service line replacement currently in violation since Nov 2020
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 703 locations within half a mile, as of December 31, 2025

Provider	Max Down / Up (Mbps)
Verizon Fiber · Fixed Wireless in parts of the area	2,300 / 2,300
Xfinity Cable · Fiber in parts of the area	2,000 / 2,000
Astound Broadband Cable	1,500 / 50
Netafy Fixed Wireless	600 / 150
AT&T Fixed Wireless	100 / 20

May also be available: T-Mobile.

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