NPI Portal NPI Lookup & Verification

Type 2 · Organization ✓ Active NPI ✓ Valid NPI checksum

Clark S. Tsai, M.D., Inc.

Ophthalmology Physician in Oakland, CA · enumerated 2011 · authorized official Clark Tsai, Ceo.

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

National Provider Identifier

1487930996

Verified

See something wrong? Report a correction

Registry record

Entity type Organization (Type 2)
Legal business name Clark S. Tsai, M.D., Inc.
Practice address 350 30th St, Suite 444, Oakland, CA, 94609
Phone (925) 864-8886
Fax (925) 689-7748
Enumeration date Oct 28, 2011
Last updated in NPPES Dec 14, 2011

Taxonomy & classification

207W00000X Ophthalmology Physician Allopathic & Osteopathic Physicians · License G76192 (CA) Primary

Authorized official

Name Clark Tsai
Title Ceo
Phone (925) 864-8886

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 is the NPI number for Clark S. Tsai, M.D., Inc.?
The NPI for Clark S. Tsai, M.D., Inc. is 1487930996, a Type 2 (organization) record in the CMS NPPES registry.
Who is the authorized official for Clark S. Tsai, M.D., Inc.?
NPPES lists Clark Tsai (Ceo) as the authorized official for this organization.

Providers at this address

Browse all →

Source: CMS NPPES (public data). Snapshot 2026-07-13. Provider record last updated 2011-12-14.