CLARK S TSAI, M.D. INC
NPI 1932476991
Ophthalmology in Oakland, CA

Q: What is Clark S Tsai, M.D. Inc's NPI number?

The NPI number for Clark S Tsai, M.D. Inc is 1932476991. It was assigned to this organization in the NPPES registry on November 18, 2011.

Q: What is Clark S Tsai, M.D. Inc's specialty?

The primary specialty registered for this NPI is Ophthalmology with taxonomy code 207W00000X.

Active since November 18, 2011

638 WEBSTER ST, SUITE 358, OAKLAND, CA 94607(925) 864-8886(925) 689-7748 Get Directions Write a Review

NPPES record last updated: December 9, 2011. Verified against the NPPES registry weekly; last sync: October 18, 2026.

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About Clark S Tsai, M.d. Inc NPPES

Official registry information on file with the National Plan and Provider Enumeration System.

CLARK S TSAI, M.D. INC (NPI 1932476991) is a healthcare organization registered as an ophthalmology in Oakland, California and active in the NPI registry since November 2011. The organization lists Clark S Tsai, Ceo/president, as its authorized official.

NPPES Registry Identity

NPI1932476991

Entity TypeOrganization

Primary Taxonomy207W00000X

Legal Business NameCLARK S TSAI, M.D. INC

Location Address638 WEBSTER ST, SUITE 358Oakland, CA 94607-4168

Mailing Address2225 Port Chicago HwyConcord, CA 94520-2051 · (925) 689-7744 · Fax (925) 689-7748

Phone(925) 864-8886

Fax(925) 689-7748

Organization SubpartNo

Authorized OfficialClark S TsaiCeo/president · (925) 864-8886

Enumeration DateNovember 18, 2011

Last NPPES UpdateDecember 9, 2011

✔ NPI 1932476991 is a valid, active identifier and passes the ISO check-digit test.

Specialties & Licenses

★ Primary SpecialtyOphthalmologyAllopathic & Osteopathic Physicians

Taxonomy Code207W00000X

License✔ Licensed in CA · G76192

Definition

An ophthalmologist has the knowledge and professional skills needed to provide comprehensive eye and vision care. Ophthalmologists are medically trained to diagnose, monitor and medically or surgically treat all ocular and visual disorders. This includes problems affecting the eye and its component structures, the eyelids, the orbit and the visual pathways. In so doing, an ophthalmologist prescribes vision services, including glasses and contact lenses.

638 WEBSTER ST, Oakland, CA 94607

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Other Identifiers 4

Medicaid00G761922CA

Medicare PINZZZ32492ZCA

Medicare NSC5415470001CA

Medicare UPINY27763CA

Group Practice 1

Group TaxonomyThis provdier is a business group of one or more individual practitioners, all of who practice with the same area of specialization.193400000X SINGLE SPECIALTY GROUP

Medicare Participation & PECOS CMS

Medicare enrollment and the clinicians who bill Medicare through this organization, from CMS.

Medicare Enrollment Status

✔

Enrolled in Medicare (PECOS)

Clark S Tsai, M.d. Inc is registered in the CMS Provider Enrollment, Chain and Ownership System (PECOS).

Clinicians Billing Medicare Through This Organization

Medicare enrollment records show 1 clinician reassigns Medicare billing to Clark S Tsai, M.D. Inc, which bills Medicare for the services this clinician delivers.

Clinician (1)

Clark Tsai, M.D.

Ophthalmology

NPI 1720096829

2700 GRANT ST STE. 100
Concord, CA 94520

(925) 689-7744

✔ PECOS✔ Accepts Medicare18 mi

Source: CMS Revalidation Reassignment List, October 2026 release. Reassignment records can lag staffing changes; confirm a current affiliation with the organization.

Frequently Asked Questions NPPES & CMS

Common questions about this NPI record, answered from the official NPPES registry and CMS datasets shown on this page.

What is Clark S Tsai, M.D. Inc's NPI number?

The NPI number for Clark S Tsai, M.D. Inc is 1932476991. It was assigned to this organization in the NPPES registry on November 18, 2011.

Where is Clark S Tsai, M.D. Inc located?

Clark S Tsai, M.D. Inc is located at 638 Webster St Suite 358, Oakland, CA 94607. The listed phone number is (925) 864-8886.

What is Clark S Tsai, M.D. Inc's specialty?

The primary specialty registered for this NPI is Ophthalmology with taxonomy code 207W00000X.

Is Clark S Tsai, M.D. Inc enrolled in Medicare?

Yes. Clark S Tsai, M.D. Inc is registered in the Medicare PECOS enrollment system.

How many clinicians bill Medicare through Clark S Tsai, M.D. Inc?

According to the CMS Revalidation Reassignment List (October 2026 release), 1 clinician (Ophthalmology) reassigns their Medicare billing to Clark S Tsai, M.D. Inc. A reassignment is filed with Medicare on form CMS-855R, signed by both the clinician and the organization, and lets the organization bill Medicare and receive payment for the clinician's services. Reassignment records can lag staffing changes; confirm a current affiliation with the organization.

When was this NPI record last updated?

The NPPES record for Clark S Tsai, M.D. Inc was last updated on December 9, 2011. NPI Profile syncs weekly with the NPPES registry data releases published by CMS. This NPI record was last updated 14 years ago. If this record has changed at CMS more recently, you can request an on-demand re-check against the live CMS registry, directly from this page.