Type 1 · Individual ✓ Active NPI ✓ Valid NPI checksum
Dr. Michael F Diffendall, OD
Optometrist in Phoenix, MD · enumerated 2006.
Data current as of Jul 13, 2026 · sourced from CMS NPPES
National Provider Identifier
1184667057
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Registry record
Entity type Individual (Type 1)
Name Dr. Michael F Diffendall
Credential OD
Sex Male
Practice address 3332 Paper Mill Rd, Phoenix, MD, 21131
Phone (410) 628-1510
Fax (410) 628-1511
Enumeration date Jun 14, 2006
Last updated in NPPES Oct 30, 2013
Taxonomy & licenses
OD · Doctor of Optometry: A licensed optometrist providing primary vision care, eye exams, and corrective lenses.
About the OD credential
Other identifiers
| Identifier | Type | State | Issuer |
|---|---|---|---|
| 403626300 | Medicaid | MD | - |
| 1086642 | Other | MD | MAMSI |
| 67500005 | Other | DC | BLUE CROSS CAREFIRST |
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
Where does Michael Diffendall practice?
The practice location on file with NPPES is in Phoenix, MD. Providers can have multiple locations; NPPES lists the primary practice address.
What is the NPI number for Michael Diffendall?
The National Provider Identifier (NPI) for Michael Diffendall is 1184667057, a Type 1 (individual) record in the CMS NPPES registry.
Other providers at this practice address
Browse all →Source: CMS NPPES (public data). Snapshot 2026-07-13. Provider record last updated 2013-10-30.