Active NPI
William Michael Cassidy, MD
- Pediatrics Physician
- Vienna, VA
National Provider Identifier
1740260306
On this page
Key facts
NPPES NPI Registry- Primary specialty
- Pediatrics Physician
- License
- 0101026293
- Practice address
- 410 Maple Ave W
5
Vienna, VA 22180 - Phone
- (703) 938-2244
- Fax
- (703) 938-3669
- NPI assigned
- Jan 19, 2006
- Sex
- Male
- Sole proprietor
- No
NPPES NPI Registry
Registry information is reported by the provider to CMS and is not verified. About this source
Specialties & licenses 1
| Specialty (taxonomy) | Code | License | State | Primary |
|---|---|---|---|---|
| Pediatrics Physician | 208000000X | 0101026293 | VA | Primary |
Addresses
Primary practice location
410 Maple Ave W
5
Vienna, VA 22180
Mailing address
10400 Eaton PL
410
Fairfax, VA 22030
Phone (703) 359-5160
Medicare participation
Medicare enrollment files- Medicare fee-for-service enrollment
- Not listed in the public Medicare enrollment file
National Provider Directory
National Provider Directory- Medicare enrollment (NPD)
- Not enrolled
- Credentials
- Doctor of Medicine
State licenses
| License | State | Type | Specialty |
|---|---|---|---|
| 0101026293 | VA | MD | Pediatrics Physician |
NPI Registry JSON
The complete NPPES record for this NPI in the NPI Registry API format.
{
"created_epoch": "1137628800000",
"enumeration_type": "NPI-1",
"last_updated_epoch": "1783900800000",
"number": "1740260306",
"addresses": [
{
"country_code": "US",
"country_name": "United States",
"address_purpose": "MAILING",
"address_type": "DOM",
"address_1": "10400 EATON PL",
"address_2": "410",
"city": "FAIRFAX",
"state": "VA",
"postal_code": "22030",
"telephone_number": "703-359-5160",
"fax_number": "703-383-9574"
},
{
"country_code": "US",
"country_name": "United States",
"address_purpose": "LOCATION",
"address_type": "DOM",
"address_1": "410 MAPLE AVE W",
"address_2": "5",
"city": "VIENNA",
"state": "VA",
"postal_code": "22180",
"telephone_number": "703-938-2244",
"fax_number": "703-938-3669"
}
],
"practiceLocations": [],
"basic": {
"last_name": "CASSIDY",
"first_name": "WILLIAM",
"middle_name": "MICHAEL",
"name_prefix": "Mr.",
"credential": "MD",
"sole_proprietor": "NO",
"sex": "M",
"enumeration_date": "2006-01-19",
"last_updated": "2026-07-13",
"status": "A"
},
"taxonomies": [
{
"code": "208000000X",
"taxonomy_group": "",
"desc": "Pediatrics",
"state": "VA",
"license": "0101026293",
"primary": true
}
],
"identifiers": [],
"endpoints": [],
"other_names": []
}Other providers in Vienna, VA
Sources for this page
- NPPES NPI Registry (CMS): identity, addresses, specialties, licenses, identifiers and endpoints. Last updated by the provider on Jul 13, 2026; self-reported and not verified by CMS. Specialty names from the NUCC taxonomy.
- National Provider Directory (CMS): practice roles, locations, licenses, networks and endpoints.