Type 1 · Individual ✓ Active NPI ✓ Valid NPI checksum

Mr. Thomas Marx Do, MD

Hospitalist Physician in Sacramento, CA · enumerated 2006.

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

National Provider Identifier

1346280245

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Registry record

Entity type Individual (Type 1)

Name Mr. Thomas Marx Do

Credential MD

Sex Male

Practice address 8120 Timberlake Way Ste 107, Sacramento, CA, 95823

Phone (916) 681-6000

Fax (916) 681-6188

Enumeration date Jun 8, 2006

Last updated in NPPES Mar 13, 2020

Taxonomy & licenses

207R00000X Internal Medicine Physician Allopathic & Osteopathic Physicians · License 0101238253 (VA) Secondary

208M00000X Hospitalist Physician Allopathic & Osteopathic Physicians · License A78702 (CA) Primary

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
184440	Other	VA	BLUE CROSS BLUE SHIELD
254185	Other	VA	KAISER PERMANENTE
496675	Other	VA	MDIPA OPTIMUM CHOICE
A78702	Other	CA	MEDICAL STATE LICENSE
010222338	Medicaid	VA	-

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 Thomas Do?

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

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Source: CMS NPPES (public data). Snapshot 2026-07-13. Provider record last updated 2020-03-13.