Son Lam Nguyen, M.D.
Internal Medicine Physician · Fairfield, CA
Son Lam Nguyen, M.D. is an internal medicine physician with a practice address in Fairfield, California, and NPI 1114119526, issued on Aug 10, 2007. Check the license (California A100779, as entered in NPPES) on the Medical Board of California; the Medicare figures below come from public CMS files.
- Name
- Son Lam Nguyen
- Credential
- M.D.
- Primary taxonomy
- Internal Medicine Physician 207R00000X
- License number
- A100779 CA
Self-reported in NPPES; status is on the state search - Practice location
- 1525 Webster St, Fairfield, CA 94533
- Phone
- (707) 423-9484
- Enumerated
- Aug 10, 2007
- Record last updated
- Oct 18, 2008 (not updated in 18 years: call before relying on the address or phone)
- Medicare enrollment
- Enrolled (PECOS I20090402000124); accepts Medicare assignment
- Entity
- Type 1 · individual
8 nearest internal medicine physician records → All 17,696 in California → Look up another NPI →
Also registered at 1525 Webster St
A shared address usually means a shared clinic or building; it does not show who employs whom.
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- Yolanda WaferOrthotic Fitter1376730788
- Fulton Zink, DDSPeriodontics1205055860
Verify Son Lam Nguyen in five checks
- 1IdentityNPI record in CMS NPPESNPI lookupConfirmed in NPPES
- 2LicenseActive license and public ordersMedical Board of California
Search for license A100779Check the board - 3Other statesLicenses and actions elsewhereDocInfo (FSMB)Not checked
- 4ExclusionsMedicare and Medicaid bansHHS-OIG exclusion listNot checked
- 5CertificationBoard certificationABMS AOA NCCPA AANPNot checked
85% fewer Medicare Part D claims than the average internal medicine physician in 2024
472 Medicare Part D claims for 162 beneficiaries, against an average of 3,176 among the 108,855 providers of this specialty who prescribed in Part D.
Most prescribed
- Losartan Potassium26 claims
- Furosemide24 claims
- Atorvastatin Calcium23 claims
- Hydralazine Hcl22 claims
- Metoprolol Succinate20 claims
- Clopidogrel17 claims
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.
The MIPS final score for 2023 (Medicare payment program): 85.5 of 100
The Merit-based Incentive Payment System score is reported for this clinician. Four categories are weighted into the final score; the average among 454,083 clinicians with a measured score was 83.5.
Source: CMS Quality Payment Program, MIPS performance year 2023; category weights for 2023 (qpp.cms.gov).
Bills Medicare through one group practice
- Permanente Medical Group IncVallejo, CA
Source: CMS Doctors and Clinicians National Downloadable File (the group practices a clinician bills Medicare through) (data.cms.gov).
Son Lam Nguyen among 17,696 internal medicine physician records in California
Son Lam Nguyen, M.D. is one of 17,696 internal medicine physician records with a practice address in California. 79% of them appear in a Medicare file (Part D prescribing, MIPS, Open Payments or Medicare group billing); this one does. Its NPI, issued in 2007, is newer than 44% of them.
- NPI issued2007 · 44% of these records are older, 44% newer
- In a Medicare fileYes · 79% of these records are
- In the CMS Doctors and Clinicians fileYes · 63% of these records are
- Graduated2004 · median 2004 among the 11,065 with a school on file
- Record last updated2008 · 61% of these records were not updated in five years or more
Source: CMS NPPES, file of Aug 9, 2026, every record with primary taxonomy 207R00000X and a California practice address; Medicare files: CMS Part D Prescribers 2024, MIPS 2023, Open Payments 2024, Doctors and Clinicians (data.cms.gov).
54 internal medicine physician records list a practice address in Fairfield
They are 54 of the 3,595 NPPES records with a practice address in Fairfield, and 17,696 internal medicine physician records in California.
All 17,696 in California → Every provider in Fairfield → Internal Medicine Physician nationwide →
The 8 internal medicine physician records with the nearest ZIP codes
- Sumera Ahmed, MDFairfield, CA 945331134180219
- Nail Amro, M.D.Fairfield, CA 945331861413551
- Shulan Ding, MDFairfield, CA 945331811075351
- Daniel Green, MDFairfield, CA 945331386731602
- Svetlana Gutierrez, M.D.Fairfield, CA 945331619990637
- Jane Hewitt, MDFairfield, CA 945331629156526
- James Horodyski, M.D.Fairfield, CA 945331184710063
- Matthew Johnson, MDFairfield, CA 945331659487395
Common questions
What is Son Lam Nguyen, M.D.'s NPI number?
Son Lam Nguyen, M.D.'s National Provider Identifier (NPI) is 1114119526, issued on Aug 10, 2007. An NPI identifies a provider in billing; it is not a license.
Where is Son Lam Nguyen, M.D. located?
The NPPES record lists a practice address at 1525 Webster St, Fairfield, CA, 94533. Phone: (707) 423-9484. Providers update this record themselves, so call before visiting.
How can I verify Son Lam Nguyen, M.D.'s license?
NPPES lists California license number A100779, 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 Son Lam Nguyen, M.D. prescribe under Medicare Part D?
In 2024, Son Lam Nguyen, M.D. had 472 Medicare Part D claims for 162 beneficiaries; the average among internal medicine physician prescribers was 3,176. Part D covers Medicare prescriptions only.
What is Son Lam Nguyen, M.D.'s MIPS final score?
The 2023 MIPS final score is 85.5 of 100. The average among 454,083 clinicians with a measured score was 83.5.
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.