NPI Portal NPI Lookup & Verification

Type 1 · Individual ✓ Active NPI ✓ Valid NPI checksum

Diane Cecilia Williams, PAC

Physician Assistant in Havre De Grace, MD · enumerated 2006 · practices at Tideway Dermatology, PA.

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

National Provider Identifier

1285609438

Verified

See something wrong? Report a correction

Registry record

Entity type Individual (Type 1)
Name Diane Cecilia Williams
Credential PAC
Sex Female
Practice address 323 S Union Ave, Havre De Grace, MD, 21078
Phone (410) 939-0961
Fax (410) 939-7832
Enumeration date Feb 21, 2006
Last updated in NPPES Feb 28, 2018

Taxonomy & licenses

363A00000X Physician Assistant Physician Assistants & Advanced Practice Nursing Providers · License C0002014 (MD) Primary
363AM0700X Medical Physician Assistant Physician Assistants & Advanced Practice Nursing Providers · License C0002014 (MD) Secondary
363AS0400X Surgical Physician Assistant Physician Assistants & Advanced Practice Nursing Providers · License C0002014 (MD) Secondary

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 is the NPI number for Diane Williams?
The National Provider Identifier (NPI) for Diane Williams is 1285609438, a Type 1 (individual) record in the CMS NPPES registry.
Where does Diane Williams practice?
The practice location on file with NPPES is in Havre De Grace, MD. Providers can have multiple locations; NPPES lists the primary practice address.

Other providers at this practice address

Browse all →

Source: CMS NPPES (public data). Snapshot 2026-07-13. Provider record last updated 2018-02-28.