Active NPI
Medical Office of John Vassallo MD PLLC
- Internal Medicine Physician
- Howell, MI
On this page
Key facts
NPPES NPI Registry- Primary specialty
- Internal Medicine Physician
- License
- 4301078585
- Legal business name
- MEDICAL OFFICE OF JOHN VASSALLO MD PLLC
- Practice address
- 4354 E Grand River Ave
Howell, MI 48843-8554 - Phone
- (517) 540-0709
- Fax
- (517) 540-1775
- NPI assigned
- Dec 5, 2006
- Last updated
- Apr 13, 2026
- Organization subpart
- No
NPPES NPI Registry
Registry information is reported by the provider to CMS and is not verified. About this source
Authorized official
- Name
- Dr. John C Vassallo, MD
- Title
- Owner
- Phone
- (517) 548-0010
Authorized official NPPES reports the official by name only. The link goes to the one practitioner connected to this organization with that name.
Specialties & licenses 1
| Specialty (taxonomy) | Code | License | State | Primary |
|---|---|---|---|---|
| Internal Medicine Physician | 207R00000X | 4301078585 | MI | Primary |
Addresses
Primary practice location
4354 E Grand River Ave
Howell, MI 48843-8554
Mailing address
4354 E Grand River Ave
Howell, MI 48843-8554
Phone (517) 540-0709
Medicare participation
Medicare enrollment files- Medicare fee-for-service enrollment
- Enrolled in MI
Enrollment records 1
Laboratory certificates & supplier records
Derived by NPIMapThese CMS records do not include an NPI. They are shown because their name and street address match this provider’s.
CLIA laboratory certificates
| CLIA number | Laboratory | Certificate | Expires |
|---|---|---|---|
| 23D2323357 | Medical Office of John Vassallo | Certificate of waiver | May 5, 2027 |
National Provider Directory
National Provider DirectoryLocations
3399 E Grand River Ave
Ste 204
Howell, MI 48843
Phone (517) 518-8316
4354 E Grand River Ave
Howell, MI 48843
Phone (517) 540-0709
Practitioners & affiliated clinicians
Practitioners 19
Individual providers connected to this organization through Medicare benefit reassignment, Care Compare group membership or National Provider Directory roles, and the practitioner matching its NPPES authorized official.
-
- Internal Medicine Physician
- Howell, MI
- NPI 1275590119
-
- Physician Assistant
- Howell, MI
- NPI 1457943888
-
- Physician Assistant
- Caledonia, MI
- NPI 1174254213
-
- Family Nurse Practitioner
- Novi, MI
- NPI 1023976032
-
- Physician Assistant
- Pinckney, MI
- NPI 1184408320
-
- Physician Assistant
- Ann Arbor, MI
- NPI 1285673210
-
- Acute Care Nurse Practitioner
- Detroit, MI
- NPI 1194473827
-
- Nurse Practitioner
- Howell, MI
- NPI 1093673782
-
- Gerontology Nurse Practitioner
- Howell, MI
- NPI 1255815882
-
- Internal Medicine Physician
- Howell, MI
- NPI 1104825504
NPI Registry JSON
The complete NPPES record for this NPI in the NPI Registry API format.
{
"created_epoch": "1165276800000",
"enumeration_type": "NPI-2",
"last_updated_epoch": "1776038400000",
"number": "1487712121",
"addresses": [
{
"country_code": "US",
"country_name": "United States",
"address_purpose": "MAILING",
"address_type": "DOM",
"address_1": "4354 E GRAND RIVER AVE",
"city": "HOWELL",
"state": "MI",
"postal_code": "488438554",
"telephone_number": "517-540-0709",
"fax_number": "517-540-1775"
},
{
"country_code": "US",
"country_name": "United States",
"address_purpose": "LOCATION",
"address_type": "DOM",
"address_1": "4354 E GRAND RIVER AVE",
"city": "HOWELL",
"state": "MI",
"postal_code": "488438554",
"telephone_number": "517-540-0709",
"fax_number": "517-540-1775"
}
],
"practiceLocations": [],
"basic": {
"organization_name": "MEDICAL OFFICE OF JOHN VASSALLO MD PLLC",
"organizational_subpart": "NO",
"enumeration_date": "2006-12-05",
"last_updated": "2026-04-13",
"certification_date": "2026-04-13",
"status": "A",
"authorized_official_last_name": "VASSALLO",
"authorized_official_first_name": "JOHN",
"authorized_official_middle_name": "C",
"authorized_official_title_or_position": "OWNER",
"authorized_official_telephone_number": "517-548-0010",
"authorized_official_name_prefix": "Dr.",
"authorized_official_credential": "MD"
},
"taxonomies": [
{
"code": "207R00000X",
"taxonomy_group": "193400000X SINGLE SPECIALTY GROUP",
"desc": "Internal Medicine",
"state": "MI",
"license": "4301078585",
"primary": true
}
],
"identifiers": [],
"endpoints": [],
"other_names": []
}
Other providers in Howell, MI
Sources for this page
- NPPES NPI Registry (CMS): identity, addresses, specialties, licenses, identifiers and endpoints. Last updated by the provider on Apr 13, 2026; self-reported and not verified by CMS. Specialty names from the NUCC taxonomy.
- Medicare enrollment (CMS PECOS): enrollments, PAC IDs and benefit reassignments.
- Medicare Care Compare (CMS): clinician profile, group practices, facility affiliations, MIPS scores and star ratings.
- National Provider Directory (CMS): practice roles, locations, licenses, networks and endpoints.