NPPES file of Aug 9, 2026

John Fonmin, MD

Family Medicine Physician · Diamond Bar, CA

John Fonmin, MD is a family medicine physician with a practice address in Diamond Bar, California, and NPI 1629147319, issued on Nov 7, 2006. Check the license (California A37367, as entered in NPPES) on the Medical Board of California; the Medicare figures below come from public CMS files.

Record from CMS NPPES, file of Aug 9, 2026 · Medicare files 2024 · method · Verify with CMS →

NPPES recordNPPES file of Aug 9, 2026
1629147319
Name
John Fonmin
Credential
MD
Primary taxonomy
Family Medicine Physician 207Q00000X
License number
A37367 CA
Self-reported in NPPES; status is on the state search
Practice location
2707 S Diamond Bar Blvd, Diamond Bar, CA 91765
Phone
(909) 594-8331
Enumerated
Nov 7, 2006
Record last updated
Jul 8, 2007 (not updated in 19 years: call before relying on the address or phone)
Fax
(909) 869-6631
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 2707 S Diamond Bar Blvd

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

  1. Kathy Ou, PHARM.DPharmacist Clinician (PhC)/ Clinical Pharmacy Specialist1366887416
  2. Jong Park, LAC.Acupuncturist1760749352
  3. Kay Yoo, D.D.S.General Practice Dentistry1295802585

Verify John Fonmin in five checks

  1. 1IdentityNPI record in CMS NPPESNPI lookupConfirmed in NPPES
  2. 2LicenseActive license and public ordersMedical Board of California
    Search for license A37367
    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

PlainDoctor does not match the HHS-OIG exclusion list to individual records: most entries carry no NPI. Search the OIG exclusion list by name.

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99% fewer Medicare Part D claims than the average family medicine physician in 2024

42 Medicare Part D claims, against an average of 3,544 among the 117,163 providers of this specialty who prescribed in Part D.

  1. John Fonmin42
  2. Specialty average3,544

Source: CMS Medicare Part D Prescribers by Provider and Drug, 2024 (data.cms.gov). Part D covers prescriptions for Medicare patients only; drugs with fewer than 11 claims are not published.

John Fonmin among 17,133 family medicine physician records in California

John Fonmin, MD is one of 17,133 family medicine 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. Its NPI, issued in 2006, is newer than 6% of them.

  • NPI issued2006 · 6% of these records are older, 59% newer
  • In a Medicare fileYes · 81% of these records are
  • In the CMS Doctors and Clinicians fileNo · 62% of these records are
  • Record last updated2007 · 58% of these records were not updated in five years or more

Source: CMS NPPES, file of Aug 9, 2026, every record with primary taxonomy 207Q00000X and a California practice address; Medicare files: CMS Part D Prescribers 2024, MIPS 2023, Open Payments 2024, Doctors and Clinicians (data.cms.gov).

25 family medicine physician records list a practice address in Diamond Bar

They are 25 of the 598 NPPES records with a practice address in Diamond Bar, and 17,133 family medicine physician records in California.

The 8 family medicine physician records with the nearest ZIP codes

  1. William FenertyDiamond Bar, CA 917651184625915
  2. David Hsieh, M.D.Diamond Bar, CA 917651891919874
  3. Lubna Isho, DODiamond Bar, CA 917651851350797
  4. Brian Koffman, MDDiamond Bar, CA 917651326049164
  5. Yann Ping Pan, MDDiamond Bar, CA 917651114250925
  6. David Rhodes, MDDiamond Bar, CA 917651518968353
  7. Yvonne Rodriguez Lawson, MDDiamond Bar, CA 917651912967233
  8. Hitendra Shah, M.D.Diamond Bar, CA 917651376614818

Common questions

What is John Fonmin, MD's NPI number?

John Fonmin, MD's National Provider Identifier (NPI) is 1629147319, issued on Nov 7, 2006. An NPI identifies a provider in billing; it is not a license.

Where is John Fonmin, MD located?

The NPPES record lists a practice address at 2707 S Diamond Bar Blvd, Diamond Bar, CA, 91765. Phone: (909) 594-8331. Providers update this record themselves, so call before visiting.

How can I verify John Fonmin, MD's license?

NPPES lists California license number A37367, 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.

How much does John Fonmin, MD prescribe under Medicare Part D?

In 2024, John Fonmin, MD had 42 Medicare Part D claims; the average among family medicine physician prescribers was 3,544. Part D covers Medicare prescriptions only.

Source: CMS National Plan and Provider Enumeration System (NPPES), file of Aug 9, 2026 (NPPES files on CMS.gov); NUCC Health Care Provider Taxonomy. Medicare files from data.cms.gov. 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.