NPPES file of Aug 9, 2026

Eugene T.y. Chan, MD

Gastroenterology Physician · Walnut Creek, CA

Eugene T.y. Chan, MD is a gastroenterology physician with a practice address in Walnut Creek, California, and NPI 1528146610, issued on Nov 2, 2006. Check the license (California G53188, as entered in NPPES) on the Medical Board of California; the federal record below is the public data PlainDoctor holds for this provider.

Record from CMS NPPES, file of Aug 9, 2026 · method · Verify with CMS →

NPPES recordNPPES file of Aug 9, 2026
1528146610
Name
Eugene T.y. Chan
Credential
MD
Primary taxonomy
Gastroenterology Physician 207RG0100X
License number
G53188 CA
Self-reported in NPPES; status is on the state search
Practice location
1425 S Main St, Walnut Creek, CA 94596
Phone
(925) 295-4000
Enumerated
Nov 2, 2006
Record last updated
Jul 8, 2007 (not updated in 19 years: call before relying on the address or phone)
Medicaid ID
00G531880 CA
Entity
Type 1 · individual
Public record from CMS NPPES (open it on the CMS NPI Registry). A record is not a license: verify it with the state board.
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Also registered at 1425 S Main St

A shared address usually means a shared clinic or building; it does not show who employs whom.

  1. Eric AaserudeEmergency Medicine Physician1811491194
  2. Derek Abbassi, MDObstetrics & Gynecology Physician1841364155
  3. Peter Ackerman, MDEmergency Medicine Physician1427435023
  4. Aaron Mark Acosta, DOEmergency Medicine Physician1538789987
  5. Basil Adad, MDOtolaryngology Physician1487732574
  6. Derek Ailes, M.D.Emergency Medical Services (Emergency Medicine) Physician1992001804

Verify Eugene T.y. Chan in five checks

  1. 1IdentityNPI record in CMS NPPESNPI lookupConfirmed in NPPES
  2. 2LicenseActive license and public ordersMedical Board of California
    Search for license G53188
    Check the board
  3. 3Other statesLicenses and actions elsewhereDocInfo (FSMB)Not checked
  4. 4ExclusionsMedicare and Medicaid bansHHS-OIG exclusion listNot checked
  5. 5CertificationBoard certificationABMS AOA NCCPA AANPNot checked
Open the California license search

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Eugene T.y. Chan among 2,140 gastroenterology physician records in California

Eugene T.y. Chan, MD is one of 2,140 gastroenterology physician records with a practice address in California. 83% of them appear in a Medicare file (Part D prescribing, MIPS, Open Payments or Medicare group billing); this one does not. Its NPI, issued in 2006, is newer than 7% of them.

  • NPI issued2006 · 7% of these records are older, 48% newer
  • In a Medicare fileNo · 83% of these records are
  • In the CMS Doctors and Clinicians fileNo · 72% of these records are
  • Record last updated2007 · 60% of these records were not updated in five years or more

Source: CMS NPPES, file of Aug 9, 2026, every record with primary taxonomy 207RG0100X and a California practice address; Medicare files: CMS Part D Prescribers 2024, MIPS 2023, Open Payments 2024, Doctors and Clinicians (data.cms.gov).

Gastroenterology Physician providers in California

There are 2,140 gastroenterology physician records in California. No Medicare prescribing, quality score, industry payment or hospital affiliation is published for this NPI.

The 8 gastroenterology physician records with the nearest ZIP codes

  1. Suyi Chang, MDWalnut Creek, CA 945961972681468
  2. Daniel Chung, MDWalnut Creek, CA 945961063590552
  3. Ming Fang, MDWalnut Creek, CA 945961366520199
  4. Steven Fredman, MDWalnut Creek, CA 945961861570962
  5. Theodore Levin, MDWalnut Creek, CA 945961720166820
  6. Oliver Lin, M.D.Walnut Creek, CA 945961497981575
  7. Katharine Ozeki, M.D.Walnut Creek, CA 945961306290838
  8. Martha Turchyn-Mazuryk, MDWalnut Creek, CA 945961497821979

Common questions

What is Eugene T.y. Chan, MD's NPI number?

Eugene T.y. Chan, MD's National Provider Identifier (NPI) is 1528146610, issued on Nov 2, 2006. An NPI identifies a provider in billing; it is not a license.

Where is Eugene T.y. Chan, MD located?

The NPPES record lists a practice address at 1425 S Main St, Walnut Creek, CA, 94596. Phone: (925) 295-4000. Providers update this record themselves, so call before visiting.

How can I verify Eugene T.y. Chan, MD's license?

NPPES lists California license number G53188, as entered by the provider. Search the Medical Board of California at https://www.mbc.ca.gov/License-Verification/default.aspx. The NPPES record confirms identity only; the state search shows license status, expiration and public orders.

Source: CMS National Plan and Provider Enumeration System (NPPES), file of Aug 9, 2026 (NPPES files on CMS.gov); NUCC Health Care Provider Taxonomy. An NPI identifies who bills; it is not a license.

Figures on PlainDoctor are read from the federal files each page names (CMS NPPES, Medicare Part D, MIPS, Open Payments; the HHS-OIG exclusion list only as counts) and from Census population estimates, with the file date shown beside them. See our editorial standards & corrections policy, the methodology behind these numbers, or report a data error. Data current as of Aug 9, 2026.