NPI Portal NPI Lookup & Verification

Type 1 · Individual ✓ Active NPI ✓ Valid NPI checksum

Dr. John Benjamin Colby, MD, PHD

Neuroradiology Physician in Greenbrae, CA · enumerated 2014.

Data current as of Jul 13, 2026 · sourced from CMS NPPES

National Provider Identifier

1700205374

Verified

See something wrong? Report a correction

Registry record

Entity type Individual (Type 1)
Name Dr. John Benjamin Colby
Credential MD, PHD
Sex Male
Practice address 250 Bon Air Rd, Greenbrae, CA, 94904
Phone (415) 925-7301
Enumeration date Apr 10, 2014
Last updated in NPPES Jul 1, 2020

Taxonomy & licenses

2085N0700X Neuroradiology Physician Allopathic & Osteopathic Physicians · License A139185 (CA) Primary
MD · Doctor of Medicine: A physician who completed medical school (allopathic medicine), residency training, and state licensure. About the MD credential

What is an NPI number?

A National Provider Identifier (NPI) is a unique 10-digit number that CMS assigns to every U.S. healthcare provider and organization under HIPAA. Type 1 NPIs identify individual providers; Type 2 NPIs identify organizations. The NPI appears on insurance claims, prescriptions, and credentialing paperwork, and never changes, even if the provider moves or changes specialty.

Read the full guide → Validate an NPI →

Frequently asked questions

What specialty is John Colby?
John Colby is registered in NPPES with the primary taxonomy of Neuroradiology Physician. The taxonomy code describes the provider's classification and area of specialization for claims and credentialing.
Is this the official NPI registry?
No. NPI Portal is a private site built on public CMS NPPES data. The official registry is npiregistry.cms.hhs.gov, operated by CMS.

Other providers at this practice address

Browse all →

Source: CMS NPPES (public data). Snapshot 2026-07-13. Provider record last updated 2020-07-01.