Type 1 · Individual ✓ Active NPI ✓ Valid NPI checksum
Dr. Douglas Leonard Cassidy, OD
Optometrist in Williamsburg, VA · enumerated 2006.
Data current as of Jul 13, 2026 · sourced from CMS NPPES
National Provider Identifier
1649347600
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Registry record
Entity type Individual (Type 1)
Name Dr. Douglas Leonard Cassidy
Credential OD
Sex Male
Practice address 4655 Monticello Ave Ste 201, Williamsburg, VA, 23188
Phone (757) 259-6823
Fax (757) 259-6826
Enumeration date Nov 28, 2006
Last updated in NPPES Nov 3, 2021
Taxonomy & licenses
OD · Doctor of Optometry: A licensed optometrist providing primary vision care, eye exams, and corrective lenses.
About the OD 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
What is the NPI number for Douglas Cassidy?
The National Provider Identifier (NPI) for Douglas Cassidy is 1649347600, a Type 1 (individual) record in the CMS NPPES registry.
Where does Douglas Cassidy practice?
The practice location on file with NPPES is in Williamsburg, VA. 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 2021-11-03.