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Single Family ResidenceResidential
$469,251$296 / ft²
TopHap EstimateOur estimate of what this home would sell for today, based on nearby sales, the home's size and features, and local price trends. It is a starting point, not an appraisal.· confidence 89How well the pricing models agreed with each other on this home. Higher means the estimate rests on stronger, more consistent data.· as of Sep 24, 2026
Last sold for $220,000 on Jun 26, 2007

21 MASCOMA ST

DORCHESTER, MA 02121
3
Beds
2
Baths
1,584 ft²
Living AreaTotal finished area of the structures, from county records. Some counties include shared space like hallways or a building gym, so it may not match a listing.
4,225 ft²
Lot SizeThe size of the land the home sits on, from county records.
2006
Year BuiltThe year the home was originally built, according to county records.
2
StoriesHow many floors the home has above ground.
6
RoomsThe total room count in county records. Counties differ on which rooms they count, so compare it loosely.
2
ParkingThe number of parking spaces on the property, including the garage.

Valuation

$469K
$416K low$523K high
Last SaleThe most recent sale price and date from the recorded deed. Transfers between family members or companies may not reflect market value.$220,000 · Jun 26, 2007

Tax & Assessment

Property TaxThe property tax billed for this tax year. It usually pays for schools, roads, and local services.$5,519 (2025)
Assessed ValueThe value the county assigns to this home to calculate property tax. It is often lower than what the home would sell for.$476,600 (2025)
Assessed LandThe share of the county's assessed value that comes from the land itself, not the buildings.$157,278
Assessed ImprovementsThe share of the county's assessed value that comes from the buildings and other structures on the land.$319,322
Assessor Market ValueThe county assessor's own opinion of market value. It is separate from our estimate and updates on the county's schedule.$370,215

Property Facts

Property TypeThe broad category the county puts this property in, such as residential or commercial.Single Family Residence
StyleThe architectural style of the home, such as ranch or colonial.Colonial
CountySUFFOLK
Lot (acres)The size of the land the home sits on, from county records.0.10
RoofThe main material covering the roof, such as asphalt shingle or tile.Asphalt
HeatingThe type of heating system in the home.Forced Air With Air Conditioning
PoolWhether the property has a pool, and what kind, such as in-ground.No

Transaction History(7)

Sales and refinances filed with the county for this home. Not every transfer is a normal sale, so check the type before comparing prices.

Assigned SchoolsThe public schools this address is zoned for. Boundaries change, so confirm with the district before you count on it.

E
Martin Luther Jr. King K-8 SchoolF
Elementary · Grades PK–8 · 0.1 mi
H
Jeremiah E. Burke High SchoolF
High · Grades 9–12 · 0.5 mi

District: Boston School District

Neighborhood · ZIP 02121These are comparison scores, not percentages. 100 equals the national average, so 150 means about 50% above average.

CrimeLocal crime compared with the rest of the country, where 100 is average. It reflects things like population density, income, and how crime gets reported.142
Air pollutionOverall air pollution compared with the rest of the country, where 100 is average. Lower is cleaner.100
EarthquakeEarthquake risk and likely building damage compared with the rest of the country, where 100 is average. Scores can run far above 100.73

Index scale: 100 = US average (tick). Lower is better.

Homes occupiedThe share of homes here that someone lives in. The rest sit empty, including vacation and for-sale homes.94%
Bachelor's or higherThe share of adults 25 and older whose highest degree is a bachelor's degree.13%
Poverty rateThe share of people whose household income falls below the federal poverty line, which varies by family size.23%
UnemploymentThe share of men 16 and older who are out of work and actively looking. Only men are counted in this figure.1.0%
PopulationHow many people live in this area.28,076
DensityPeople per square mile. Higher numbers mean a more crowded, urban area.22,114 / mi²
Median incomeThe middle household income here — half of households earn more, half earn less.$45,811
Average incomeThe average household income. It runs higher than the median when a few high earners pull it up.$77,928
Average tempThe average temperature here across a full year.50°F
Annual precipHow much rain and melted snow falls here in a typical year.47 in
SunshineThe share of daylight hours that get direct sun in a typical year, counting cloud cover.58%

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Data by ATTOM. Valuations are automated estimates, not appraisals. Photos from Google Street View and may not depict the current property state.

How this home compares

21 Mascoma St measured against every home in its neighborhood, its ZIP code and its county, using county assessor records refreshed nightly. A home can stand out in one of those areas and look ordinary in another, because each one holds a different mix of homes.

  • Worth less than 86% of homes in Suffolk County
  • Costs less per square foot than 98% of homes in Suffolk County
  • Smaller than 82% of homes in Dorchester 02121
  • Has a bigger lot than 67% of homes in Suffolk County
  • Newer than 94% of homes in Dorchester 02121

What homes are worth in Dorchester 02121

Each bar is how many homes fall in that price range. The marker is this home.

This home
$235K$908K

This home is worth more than 38% of homes in Dorchester 02121.

How it measures up in Dorchester 02121

The dot is this home. The mark in the middle is the typical home in Dorchester 02121.

Estimated value$469,251
CheaperTypical $514,164Pricier

Pricier than 38% of homes nearby

Price per ft²$296
CheaperTypical $356Pricier

Pricier than 26% of homes nearby

Living area1,584 ft²
SmallerTypical 3,264 ft²Bigger

Bigger than 18% of homes nearby

Lot size4,225 ft²
SmallerTypical 4,269 ft²Bigger

Bigger than 49% of homes nearby

Year built2006
OlderTypical 1905Newer

Newer than 94% of homes nearby

How 21 Mascoma St ranks against every home in each area.
MeasureThis homeDorchesterDorchester 02121Suffolk County
Estimated valuepricier than$469,25122% of homes38% of homes14% of homes
Price per ft²pricier than$2969% of homes26% of homes2% of homes
Living areabigger than1,584 ft²33% of homes18% of homes54% of homes
Lot sizebigger than4,225 ft²62% of homes49% of homes67% of homes
Year builtnewer than200693% of homes94% of homes90% of homes

About 21 Mascoma St

How much is 21 Mascoma St, Dorchester, MA worth?

The TopHap Estimate for 21 Mascoma St, Dorchester, MA is $469,251 as of Sep 24, 2026. The likely range is $415,839 to $522,663. The estimate is modelled from recorded sales, assessments and the property's own characteristics — it is not an appraisal.

When did 21 Mascoma St, Dorchester, MA last sell?

21 Mascoma St, Dorchester, MA last sold on Jun 26, 2007 for $220,000, according to the county's recorded deed. TopHap holds 2 recorded sales for this parcel.

How big is 21 Mascoma St, Dorchester, MA?

21 Mascoma St, Dorchester, MA has 3 bedrooms, 2 bathrooms, 1,584 square feet of living space and a 0.10-acre lot.

When was 21 Mascoma St, Dorchester, MA built?

21 Mascoma St, Dorchester, MA was built in 2006, making it 20 years old. It is a colonial home. The building has 2 stories.

What schools serve 21 Mascoma St, Dorchester, MA?

21 Mascoma St, Dorchester, MA is assigned to Martin Luther Jr. King K-8 School (elementary), rated F; Jeremiah E. Burke High School (high), rated F. All sit in Boston School District. Attendance boundaries change — confirm with the district before relying on an assignment.

How does 21 Mascoma St, Dorchester, MA compare to other homes in Dorchester 02121?

Among the 2,911 homes in Dorchester 02121, it is worth more than 38% of them ($469,251 against a typical $514,164), its price per square foot is higher than 26% of them ($296 against a typical $356), it is bigger than 18% of them (1,584 ft² against a typical 3,264 ft²), its lot is bigger than 49% of them (4,225 ft² against a typical 4,269 ft²) and it is newer than 94% of them (2006 against a typical 1905). Measured against all of Suffolk County, it is worth more than 14% of homes there. These shares are recounted nightly from the full county assessor record for each area, not from active listings.

What are the property taxes on 21 Mascoma St, Dorchester, MA?

The 2025 property tax bill for 21 Mascoma St, Dorchester, MA was $5,519. The county assessed it at $476,600.

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