Type 1 · Individual ✓ Active NPI ✓ Valid NPI checksum Sole proprietor

Dr. Andrea S. Tieng, M.D.

Gastroenterology Physician in Rancho Cucamonga, CA · enumerated 2008.

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

National Provider Identifier

1356528566

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Registry record

Entity type Individual (Type 1)

Name Dr. Andrea S. Tieng

Credential M.D.

Sex Female

Practice address Rancho Cucamonga, CA, 91730

Phone (909) 255-7200

Fax (909) 255-7215

Enumeration date Jan 30, 2008

Last updated in NPPES Jan 27, 2022

Street address withheld: NPPES sole-proprietor addresses can be home addresses. See our data policy.

Taxonomy & licenses

207RG0100X Gastroenterology Physician Allopathic & Osteopathic Physicians · License 241597 (NY) Secondary

207RG0100X Gastroenterology Physician Allopathic & Osteopathic Physicians · License A106477 (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
241597	Other	NY	MEDICAL LICENSE
A106477	Other	CA	MEDICAL LICENSE

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 → Validate an NPI →

Frequently asked questions

What specialty is Andrea Tieng?

Andrea Tieng is registered in NPPES with the primary taxonomy of Gastroenterology Physician. 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 2026-07-13. Provider record last updated 2022-01-27.