NPPES file of Aug 9, 2026

Tam K. Nguyen, M.D.

Internal Medicine Physician · Garden Grove, CA

Tam K. Nguyen, M.D. is an internal medicine physician with a practice address in Garden Grove, California, and NPI 1720153182, issued on Nov 21, 2006. Check the license (California A55848, 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
1720153182
Name
Tam K. Nguyen
Credential
M.D.
Primary taxonomy
Internal Medicine Physician 207R00000X
License number
A55848 CA
Self-reported in NPPES; status is on the state search
Practice location
12221 Brookhurst St Ste 100, Garden Grove, CA 92840
Phone
(714) 805-8260
Enumerated
Nov 21, 2006
Record last updated
Apr 22, 2023
Fax
(714) 908-8086
Medicare enrollment
Enrolled (PECOS I20120328000989); accepts Medicare assignment
Medical or professional school
Tulane University School Of Medicine, 1994
Telehealth
Offers telehealth (CMS)
Entity
Type 1 · individual
Public record from CMS NPPES (open it on the CMS NPI Registry). Enrollment, assignment, school and telehealth: CMS Doctors and Clinicians file, Aug 2026. A record is not a license: verify it with the state board.
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Verify Tam K. Nguyen in five checks

  1. 1IdentityNPI record in CMS NPPESNPI lookupConfirmed in NPPES
  2. 2LicenseActive license and public ordersMedical Board of California
    Search for license A55848
    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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2.2 times the Medicare Part D claims of the average internal medicine physician in 2024

7,125 Medicare Part D claims for 270 beneficiaries, against an average of 3,176 among the 108,855 providers of this specialty who prescribed in Part D. Brand-name drugs were 31% of claims. 32 claims were for opioids.

  1. Tam Nguyen7,125
  2. Specialty average3,176

Most prescribed

  1. Azithromycin465 claims
  2. Oseltamivir Phosphate317 claims
  3. Privigen283 claims
  4. Hydroxychloroquine Sulfate271 claims
  5. Januvia271 claims
  6. Mirtazapine242 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: $122.09

6 payments; by number, the most common kind was food and beverage; the largest payer was Regeneron Healthcare Solutions, 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.

  1. Tam Nguyen$122.09
  2. Specialty average$1,303.06

Source: CMS Open Payments, program year 2024 (openpaymentsdata.cms.gov); average among providers of this specialty with at least one payment.

Tam K. Nguyen among 17,696 internal medicine physician records in California

Tam K. 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 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
  • Graduated1994 · median 2004 among the 11,065 with a school on file
  • Record last updated2023 · 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).

39 internal medicine physician records list a practice address in Garden Grove

They are 39 of the 4,572 NPPES records with a practice address in Garden Grove, and 17,696 internal medicine physician records in California.

The 8 internal medicine physician records with the nearest ZIP codes

  1. Negin Behazin, MDGarden Grove, CA 928401497076301
  2. Bryan Choi, MDGarden Grove, CA 928401255525499
  3. Danh Dan, M.D.Garden Grove, CA 928401790917631
  4. Edward Ko, M.D.Garden Grove, CA 928401396911798
  5. Adriana Longo, M.D.Garden Grove, CA 928401124004999
  6. Benjamin Navarro, M.D.Garden Grove, CA 928401033208608
  7. Tan Nguyen, M.D.Garden Grove, CA 928401609839299
  8. Nga Nguyen, M.D.Garden Grove, CA 928401346447984

Common questions

What is Tam K. Nguyen, M.D.'s NPI number?

Tam K. Nguyen, M.D.'s National Provider Identifier (NPI) is 1720153182, issued on Nov 21, 2006. An NPI identifies a provider in billing; it is not a license.

Where is Tam K. Nguyen, M.D. located?

The NPPES record lists a practice address at 12221 Brookhurst St Ste 100, Garden Grove, CA, 92840. Phone: (714) 805-8260. Providers update this record themselves, so call before visiting.

How can I verify Tam K. Nguyen, M.D.'s license?

NPPES lists California license number A55848, 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 K. Nguyen, M.D. prescribe under Medicare Part D?

In 2024, Tam K. Nguyen, M.D. had 7,125 Medicare Part D claims for 270 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.