Type 1 · Individual ✓ Active NPI ✓ Valid NPI checksum

Stephen Tseng, MD

Internal Medicine Physician in Ione, CA · enumerated 2006 · practices at Cdcr.

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

National Provider Identifier

1346328077

Verified

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Registry record

Entity type Individual (Type 1)

Name Stephen Tseng

Credential MD

Sex Male

Practice address 4001 Highway 104, Ione, CA, 95640

Phone (209) 274-4911

Enumeration date Nov 1, 2006

Last updated in NPPES Oct 24, 2008

Taxonomy & licenses

207R00000X Internal Medicine Physician Allopathic & Osteopathic Physicians · License A69139 (CA) Primary

208M00000X Hospitalist Physician Allopathic & Osteopathic Physicians · License A69139 (CA) Secondary

MD · Doctor of Medicine: A physician who completed medical school (allopathic medicine), residency training, and state licensure. About the MD credential

Other identifiers

Identifier	Type	State	Issuer
00A691390	Medicaid	CA	-

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

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.

What specialty is Stephen Tseng?

Stephen Tseng is registered in NPPES with the primary taxonomy of Internal Medicine Physician. The taxonomy code describes the provider's classification and area of specialization for claims and credentialing.

Other providers at this practice address

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Jalal Soltanian-Zadeh Family Medicine Physician · Ione, CA NPI 1962554196 Megan Lowry Psychologist · Ione, CA NPI 1093842650 Christopher Smith Internal Medicine Physician · Ione, CA NPI 1770782302 Richard Galloway General Practice Physician · Ione, CA NPI 1114109568 Edwin Williams Dentist · Ione, CA NPI 1952584005 Bradley Archibald Dentist · Ione, CA NPI 1083897029 Wesley Hashimoto Internal Medicine Physician · Ione, CA NPI 1902080112 Brett Williams General Practice Physician · Ione, CA NPI 1194909044

Source: CMS NPPES (public data). Snapshot 2026-07-13. Provider record last updated 2008-10-24.