Type 1 · Individual ✓ Active NPI ✓ Valid NPI checksum
Dr. Gregory T. Whitman, M.D.
Neurology Physician in Irvine, CA · enumerated 2006.
Data current as of Jul 13, 2026 · sourced from CMS NPPES
National Provider Identifier
1356403851
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Registry record
Entity type Individual (Type 1)
Name Dr. Gregory T. Whitman
Credential M.D.
Sex Male
Practice address 16405 Sand Canyon Ave Ste 220, Irvine, CA, 92618
Phone (949) 336-8150
Fax (949) 727-7016
Enumeration date Dec 14, 2006
Last updated in NPPES Oct 3, 2018
Taxonomy & licenses
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.
Frequently asked questions
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.
What specialty is Gregory Whitman?
Gregory Whitman is registered in NPPES with the primary taxonomy of Neurology Physician. The taxonomy code describes the provider's classification and area of specialization for claims and credentialing.
Other providers at this practice address
Browse all → Bruce Cleeremans Neurology Physician · Irvine, CA NPI 1205042249 Lauren Bennett Clinical Neuropsychologist · Irvine, CA NPI 1811426125 Gregory T Whitman MD Inc Neurology Physician · Irvine, CA NPI 1467932160 Ruth Morin Clinical Psychologist · Irvine, CA NPI 1992366314 Michelle Mcdonnell Clinical Neuropsychologist · Irvine, CA NPI 1770248809 Oc Neuropsych, A Psychological Corporation Clinical Neuropsychologist · Irvine, CA NPI 1487473575 Melvin Castillo Student in an Organized Health Care Education/Training Program · Irvine, CA NPI 1043148240
Source: CMS NPPES (public data). Snapshot 2026-07-13. Provider record last updated 2018-10-03.