NPPES file of Aug 9, 2026

Michael Gerard Lyon, M.D.

Rheumatology Physician · Livermore, CA

Michael Gerard Lyon, M.D. is a rheumatology physician with a practice address in Livermore, California, and NPI 1255357968, issued on Jul 14, 2006. Check the license (California G47269, 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
1255357968
Name
Michael Gerard Lyon
Credential
M.D.
Primary taxonomy
Rheumatology Physician 207RR0500X
License number
G47269 CA
Self-reported in NPPES; status is on the state search
Practice location
4951 Arroyo RD, Livermore, CA 94550
Phone
(650) 493-5000
Enumerated
Jul 14, 2006
Record last updated
Jul 9, 2007 (not updated in 19 years: call before relying on the address or phone)
Fax
(925) 449-6522
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 →

Also registered at 4951 Arroyo RD

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

  1. Sheila AlmiranezRegistered Nurse1194915199
  2. Rowena Anselmo, RNRegistered Nurse1275371973
  3. Ryan BarrettClinical Social Worker1629534185
  4. Peggy Berry, RN; LMFTPsychiatric/Mental Health Registered Nurse1902904097
  5. Anna Black, AU.D.Audiologist1740585702
  6. Samantha Bonilla, MSWSocial Worker1518777184

Verify Michael Gerard Lyon in five checks

  1. 1IdentityNPI record in CMS NPPESNPI lookupConfirmed in NPPES
  2. 2LicenseActive license and public ordersMedical Board of California
    Search for license G47269    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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Michael Gerard Lyon among 926 rheumatology physician records in California

Michael Gerard Lyon, M.D. 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 2006, is newer than 6% of them.

  • NPI issued2006 · 6% of these records are older, 55% newer
  • In a Medicare fileNo · 81% of these records are
  • In the CMS Doctors and Clinicians fileNo · 69% of these records are
  • Record last updated2007 · 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 Livermore → Rheumatology Physician nationwide →

The 8 rheumatology physician records with the nearest ZIP codes

  1. Thomas Jamison, MDMartinez, CA 945531336227404
  2. Brittany Goss, D.O.Napa, CA 945581093911356
  3. Naini Sharma, MDFremont, CA 945391659602027
  4. Christine Elias, M.D.Fremont, CA 945381972732600
  5. Peter Hendler, MDFremont, CA 945381659456325
  6. Barry Shibuya, M.D.Fremont, CA 945381275746935
  7. Robert Su, M.D.Fremont, CA 945381932439932
  8. Vani Velkuru, M.D.Fremont, CA 945381811174428

Common questions

What is Michael Gerard Lyon, M.D.'s NPI number?

Michael Gerard Lyon, M.D.'s National Provider Identifier (NPI) is 1255357968, issued on Jul 14, 2006. An NPI identifies a provider in billing; it is not a license.

Where is Michael Gerard Lyon, M.D. located?

The NPPES record lists a practice address at 4951 Arroyo RD, Livermore, CA, 94550. Phone: (650) 493-5000. Providers update this record themselves, so call before visiting.

How can I verify Michael Gerard Lyon, M.D.'s license?

NPPES lists California license number G47269, 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.