3700-20 MARKET ST
OFF BLD N/PKG N/COM MASON · Philadelphia · 19104
At a glance
3700-20 MARKET ST in Philadelphia, PA is listed on the Philadelphia property roll as “OFF BLD N/PKG N/COM MASON”, OPA account 883077500. The roll records 51,165 sq ft of building area, 3 floors, a 1973 build year and an assessed value of $13,206,300. 1 active business locations at this address appear in public records.
Public record — 1 matched business locations
Tenants & business locations
| Company | Suite / floor | Since | Source | Match |
|---|---|---|---|---|
| NATIONAL BOARD OF MEDICAL EXAMINERS | — | Nov 2010 | Philadelphia L&I licence | folio match · high |
Philadelphia assessment roll
Parcel record
| Field | Value |
|---|---|
| OPA account | 883077500 |
| Site address | 3700-20 MARKET ST |
| Land use (DOR) | DD0 — OFF BLD N/PKG N/COM MASON |
| Building area (actual) | 51,165 sq ft |
| Floors / units / buildings | 3 / — / — |
| Lot size | — |
| Year built | 1973 |
| Zoning (primary) | — |
| Land value | — |
| Building value | — |
| Total assessed value | $13,206,300 |
Recorded owner (assessment roll)
NATIONAL BOARD OF MEDICAL
Owner mailing address: 3750 MARKET ST, PHILADELPHIA, PA, 19104
2 Philadelphia office properties share this owner mailing address →
Commercial property is usually held one building per entity; a shared mailbox is how the roll reveals a portfolio. It is evidence of common ownership, not proof.
Location
- Address
- 3700-20 MARKET ST
- City
- Philadelphia
- ZIP
- 19104
- Coordinates
- 39.95603, -75.19663
Within ~650 m
Nearby office buildings
- 3521-35 MARKET ST2 tenants
473,400 sq ft · 1974
- 25 N 38TH ST0 tenants
428,400 sq ft · 13 fl · 2024
- 3711L MARKET ST0 tenants
356,362 sq ft · 14 fl · 2015
- 3655-75 MARKET ST4 tenants
295,293 sq ft · 14 fl · 2018
- 3701 MARKET ST1 tenants
172,000 sq ft · 2000
- 3722-46 MARKET ST0 tenants
165,000 sq ft · 1993
How does 3700-20 MARKET ST compare with other Philadelphia office buildings?
At 51,165 sq ft, 3700-20 MARKET ST is about 41% larger than the average office building on the Philadelphia roll, which comes to 36,284 sq ft across 2,470 buildings.
Its assessed value works out to $258 per square foot of building area, against $163 across all office floor area on the roll.
Does the owner of 3700-20 MARKET ST hold other Philadelphia office property?
2 Philadelphia office properties (2 parcels, 216.2K sq ft) are recorded to 2 owner entities sharing this parcel's tax-bill mailing address. A shared mailing address is evidence of common ownership, not proof of it.
What does “OFF BLD N/PKG N/COM MASON” mean for this parcel?
The Philadelphia roll classifies OPA account 883077500 as “OFF BLD N/PKG N/COM MASON” (use code DD0). BuildingCensus includes a parcel in its office census when the roll gives it an office-class use, so the label is the county's, not an inference.
Frequently asked questions
Who owns 3700-20 MARKET ST?
The recorded owner on the Philadelphia assessment roll (current) is NATIONAL BOARD OF MEDICAL. Owner mailing address on file: 3750 MARKET ST, PHILADELPHIA, PA, 19104.
What companies have offices at 3700-20 MARKET ST?
1 active business locations at this building appear in Philadelphia public records, including NATIONAL BOARD OF MEDICAL EXAMINERS. Public records under-count tenants that don't hold a local receipt or register the address.
How big is 3700-20 MARKET ST?
The Philadelphia roll records 51,165 sq ft of building area, 3 floors, a build year of 1973.
What is the assessed value of 3700-20 MARKET ST?
$13,206,300 on the Philadelphia roll. Assessed values are taxable-roll figures, not market prices.
What is the OPA account for 3700-20 MARKET ST?
OPA account 883077500, site address 3700-20 MARKET ST, Philadelphia. It is the key to look the parcel up in the Office of Property Assessment nightly roll (Philadelphia).
More around 3700-20 MARKET ST
Everything here comes from public records, and public records go stale. If you know better, say so.
Data provenance — public records only
- Philadelphia — Office of Property Assessment nightly roll (owner and mailing address on every parcel), Department of Records deed transfers with consideration and counterparties, and L&I business licences joined by OPA account. The universal Commercial Activity licence roll publishes no premises addresses, so occupancy shows regulated activities only.
Every fact on this page is drawn from the government records above — no listing sites, no scraped platforms, no third-party images. Facts from public records are uncopyrightable; each tenancy row carries its source and match confidence. Records can lag reality — a business-tax receipt or registration at an address is evidence of occupancy, not a lease confirmation.
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Dataset updated . Source: Philadelphia assessment roll, OPA account 883077500.
About this data
Source: Office of Property Assessment nightly roll (Philadelphia), as published October 10, 2026. See the methodology for how records are matched, cleaned and scored.
Cite as: BuildingCensus, “3700-20 MARKET ST, Philadelphia, PA (OPA account 883077500)”, https://buildingcensus.com/offices/philly/office-building-36c98bf0 (data as of October 10, 2026).