NPPES file of Aug 9, 2026

Happy Chan

Rheumatology Physician · Davis, CA

Happy Chan is a rheumatology physician with a practice address in Davis, California, and NPI 1740409218, issued on Apr 24, 2007. Check the license (California 20A8277, 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
1740409218
Name
Happy Chan
Primary taxonomy
Rheumatology Physician 207RR0500X
License number
20A8277 CA
Self-reported in NPPES; status is on the state search
Practice location
451 E Health Sciences Drive Gbsf Suite 6510, Davis, CA 95616
Phone
(530) 752-2884
Enumerated
Apr 24, 2007
Record last updated
Sep 11, 2011 (not updated in 15 years: call before relying on the address or phone)
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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8 nearest rheumatology physician records → All 926 in California → Look up another NPI →

Verify Happy 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 20A8277    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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Happy Chan among 926 rheumatology physician records in California

Happy Chan is one of 926 rheumatology physician records with a practice address in California. 81% 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 2007, is newer than 45% of them.

  • NPI issued2007 · 45% of these records are older, 42% newer
  • In a Medicare fileNo · 81% of these records are
  • In the CMS Doctors and Clinicians fileNo · 69% of these records are
  • Record last updated2011 · 62% of these records were not updated in five years or more

Source: CMS NPPES, file of Aug 9, 2026, every record with primary taxonomy 207RR0500X and a California practice address; Medicare files: CMS Part D Prescribers 2024, MIPS 2023, Open Payments 2024, Doctors and Clinicians (data.cms.gov).

Rheumatology Physician providers in California

There are 926 rheumatology physician records in California. No Medicare prescribing, quality score, industry payment or hospital affiliation is published for this NPI.

All 926 in California → Every provider in Davis → Rheumatology Physician nationwide →

The 8 rheumatology physician records with the nearest ZIP codes

  1. James Castles, M.D.Davis, CA 956161477623403
  2. Gurtej Cheema, M.D.Davis, CA 956161578546578
  3. Merrill GershwinDavis, CA 956161881677268
  4. Stanley Naguwa, M.D.Davis, CA 956161447231873
  5. Dick Robbins, MDDavis, CA 956161972586352
  6. Shraddha Jatwani, MDSacramento, CA 956201063641017
  7. Thitinan Srikulmontree, M.D.Citrus Heights, CA 956211699722603
  8. Christine Fernando, MDCarmichael, CA 956081962580605

Common questions

What is Happy Chan's NPI number?

Happy Chan's National Provider Identifier (NPI) is 1740409218, issued on Apr 24, 2007. An NPI identifies a provider in billing; it is not a license.

Where is Happy Chan located?

The NPPES record lists a practice address at 451 E Health Sciences Drive Gbsf Suite 6510, Davis, CA, 95616. Phone: (530) 752-2884. Providers update this record themselves, so call before visiting.

How can I verify Happy Chan's license?

NPPES lists California license number 20A8277, 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.

Written with AI tools from the named public files; every figure is computed from those files (how it is made).

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.