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Dr. Peter James Mazolewski, M.D.

Surgery Physician in Walnut Creek, CA · enumerated 2006.

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

National Provider Identifier

1710076773

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Registry record

Entity type Individual (Type 1)
Name Dr. Peter James Mazolewski
Credential M.D.
Sex Male
Practice address 365 Lennon Ln Ste 290, Walnut Creek, CA, 94598
Phone (925) 658-5076
Fax (925) 658-5089
Enumeration date Oct 11, 2006
Last updated in NPPES Feb 26, 2025

Taxonomy & licenses

174400000X Specialist Other Service Providers · License A84094 (CA) Secondary
208600000X Surgery Physician Allopathic & Osteopathic Physicians · License A84094 (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.

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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 Peter Mazolewski?
Peter Mazolewski is registered in NPPES with the primary taxonomy of Surgery Physician. The taxonomy code describes the provider's classification and area of specialization for claims and credentialing.

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Source: CMS NPPES (public data). Snapshot 2026-07-13. Provider record last updated 2025-02-26.