Tam M. Nguyen, D.O.
Internal Medicine Physician · Marysville, CA
Tam M. Nguyen, D.O. is an internal medicine physician with a practice address in Marysville, California, and NPI 1841200854, issued on Aug 9, 2006. Check the license (California 20A8322, as entered in NPPES) on the Medical Board of California; the Medicare figures below come from public CMS files.
- Name
- Tam M. Nguyen
- Credential
- D.O.
- Primary taxonomy
- Internal Medicine Physician 207R00000X
- License number
- 20A8322 CA
Self-reported in NPPES; status is on the state search - Practice location
- 414 G St, Marysville, CA 95901
- Phone
- (530) 741-2393
- Enumerated
- Aug 9, 2006
- Record last updated
- Feb 11, 2022
- Fax
- (530) 741-2396
- Medicare enrollment
- Enrolled (PECOS I20040708000873); accepts Medicare assignment
- Medical or professional school
- Philadelphia College Of Osteopathic Medicine, 1998
- Telehealth
- Offers telehealth (CMS)
- Entity
- Type 1 · individual
8 nearest internal medicine physician records → All 17,696 in California → Look up another NPI →
Also registered at 414 G St
A shared address usually means a shared clinic or building; it does not show who employs whom.
- Teresa Carter, FNPNurse Practitioner1790912384
- Michael Chin, MDCardiovascular Disease Physician1083680466
- Jennifer Duncan, N.PNurse Practitioner1043495021
- Samantha Geweke, PAMedical Physician Assistant1992719322
- Hari Goyal, M.D.Internal Medicine Physician1770571515
- Karanbir Grewal, M.D.Interventional Cardiology Physician1235105610
Verify Tam M. Nguyen in five checks
- 1IdentityNPI record in CMS NPPESNPI lookupConfirmed in NPPES
- 2LicenseActive license and public ordersMedical Board of California
Search for license 20A8322Check the board - 3Other statesLicenses and actions elsewhereDocInfo (FSMB)Not checked
- 4ExclusionsMedicare and Medicaid bansHHS-OIG exclusion listNot checked
- 5CertificationBoard certificationABMS AOA NCCPA AANPNot checked
3.0 times the Medicare Part D claims of the average internal medicine physician in 2024
9,435 Medicare Part D claims for 864 beneficiaries, against an average of 3,176 among the 108,855 providers of this specialty who prescribed in Part D. Brand-name drugs were 9% of claims. 594 claims were for opioids.
Most prescribed
- Atorvastatin Calcium567 claims
- Amlodipine Besylate442 claims
- Levothyroxine Sodium382 claims
- Lisinopril330 claims
- Hydrocodone-Acetaminophen288 claims
- Losartan Potassium262 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.
Industry payments in 2024: $38.44
2 payments; by number, the most common kind was food and beverage; the largest payer was Sumitomo Pharma America, Inc. The 50,334 providers of this specialty with any payment received $1,303.06 on average. Payments are reported by manufacturers, not by the provider, and are not a sign of wrongdoing.
Source: CMS Open Payments, program year 2024 (openpaymentsdata.cms.gov); average among providers of this specialty with at least one payment.
Bills Medicare through one group practice
- Permanente Medical Group IncRoseville, CA
Source: CMS Doctors and Clinicians National Downloadable File (the group practices a clinician bills Medicare through) (data.cms.gov).
Tam M. Nguyen among 17,696 internal medicine physician records in California
Tam M. Nguyen, D.O. 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 2006, is newer than 5% of them.
- NPI issued2006 · 5% of these records are older, 56% newer
- In a Medicare fileYes · 79% of these records are
- In the CMS Doctors and Clinicians fileYes · 63% of these records are
- Graduated1998 · median 2004 among the 11,065 with a school on file
- Record last updated2022 · 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).
10 internal medicine physician records list a practice address in Marysville
They are 10 of the 708 NPPES records with a practice address in Marysville, and 17,696 internal medicine physician records in California.
All 17,696 in California → Every provider in Marysville → Internal Medicine Physician nationwide →
The 8 internal medicine physician records with the nearest ZIP codes
- Hari Goyal, M.D.Marysville, CA 959011770571515
- Jerry Gross, D.O.Marysville, CA 959011386647709
- Shalini Gupta, M.D.Marysville, CA 959011891783692
- Dilip K CMarysville, CA 959011528684818
- Kaumakaokalani Shimatsu, M.D.Marysville, CA 959011194014357
- Nathan Tang, M.D.Marysville, CA 959011215947247
- Baljinder Virdi, MDMarysville, CA 959011811383789
- Bisrat Woldemichael, MDMarysville, CA 959011568022663
Common questions
What is Tam M. Nguyen, D.O.'s NPI number?
Tam M. Nguyen, D.O.'s National Provider Identifier (NPI) is 1841200854, issued on Aug 9, 2006. An NPI identifies a provider in billing; it is not a license.
Where is Tam M. Nguyen, D.O. located?
The NPPES record lists a practice address at 414 G St, Marysville, CA, 95901. Phone: (530) 741-2393. Providers update this record themselves, so call before visiting.
How can I verify Tam M. Nguyen, D.O.'s license?
NPPES lists California license number 20A8322, 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 Tam M. Nguyen, D.O. prescribe under Medicare Part D?
In 2024, Tam M. Nguyen, D.O. had 9,435 Medicare Part D claims for 864 beneficiaries; the average among internal medicine physician prescribers was 3,176. 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.