Mr. Thomas Henry Diffenderfer

Mr. Thomas Henry Diffenderfer is a Other Technician provider (Technician, Other) practicing in San Leandro, CA, registered in the NPPES registry with NPI 1790923662 since 2009.

✓ Active NPI ✓ Valid NPI checksum

NPI	1790923662
Entity type	Individual (Type 1)
Name	Mr. Thomas Henry Diffenderfer
Sex	Male
Practice address	2275 ARLINGTON DR, San Leandro, CA, 94578
Phone	5103171444
Enumeration date	2009-01-29
Last updated in NPPES	2009-01-29

Taxonomy & licenses

Taxonomy code	Specialty	Primary	License	State
247200000X	Other Technician	Primary	—	—

Copy-ready billing details

Provider: Thomas Diffenderfer
NPI: 1790923662
Taxonomy: 247200000X (Other Technician)
Address: 2275 ARLINGTON DR, San Leandro, CA, 94578

Other providers at this practice address

NPI	Name	Type	Specialty	Location
1114001906	Seneca Family of Agencies	Organization	Community/Behavioral Health Agency	San Leandro, CA
1144399148	Jill Mason	Individual	Clinical Social Worker	San Leandro, CA
1619046521	Julie Hess	Individual	Clinical Social Worker	San Leandro, CA
1225108285	Kathryn Coy	Individual	Clinical Social Worker	San Leandro, CA
1215007802	Erica Kellenbach	Individual	Clinical Social Worker	San Leandro, CA
1801967542	Kari Sundstrom	Individual	Clinical Social Worker	San Leandro, CA
1972674612	Michael Mertz	Individual	Professional Counselor	San Leandro, CA
1942371596	Amy Love	Individual	Marriage & Family Therapist	San Leandro, CA

Verify this record

Cross-check NPI 1790923662 against the authoritative CMS record: view Mr. Thomas Henry Diffenderfer on the official NPPES registry .

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 or validate an NPI number.

Frequently asked questions

What specialty is Thomas Diffenderfer?

Thomas Diffenderfer is registered in NPPES with the primary taxonomy of Other Technician. The taxonomy code describes the provider's classification and area of specialization for claims and credentialing.

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.

Source: CMS NPPES (public data). Snapshot 2026-07-11. Provider record last updated 2009-01-29.