NPI Portal NPI Lookup & Verification

Type 1 · Individual ✓ Active NPI ✓ Valid NPI checksum Sole proprietor

Dr. William H Diamant, PHARM.D.

Pharmacist in Norwalk, CA · enumerated 2011 · practices at Walgreen Co.

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

National Provider Identifier

1033491568

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Registry record

Entity type Individual (Type 1)
Name Dr. William H Diamant
Credential PHARM.D.
Sex Male
Practice address Norwalk, CA, 90650
Phone (562) 864-8138
Fax (562) 929-8489
Enumeration date Sep 10, 2011
Last updated in NPPES Sep 10, 2011

Street address withheld: NPPES sole-proprietor addresses can be home addresses. See our data policy.

Taxonomy & licenses

183500000X Pharmacist Pharmacy Service Providers · License RPH30352 (CA) Primary
PHARMD · Doctor of Pharmacy: A licensed pharmacist with a professional doctorate in pharmacy. About the PHARMD 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

How do I verify William Diamant's NPI record?
Cross-check NPI 1033491568 against the official CMS registry at npiregistry.cms.hhs.gov. This page mirrors the same public NPPES data with a monthly snapshot.
Is NPI 1033491568 active?
Yes, as of the latest NPPES snapshot, NPI 1033491568 is active (record last updated 2011-09-10).

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Source: CMS NPPES (public data). Snapshot 2026-07-13. Provider record last updated 2011-09-10.