Tan Nguyen, M.D.
NPI 1609839299 · Internal Medicine Physician · Garden Grove, CA
Enrolled with Medicare as Practitioner - Internal Medicine · source: CMS PECOS Public Provider Enrollment (2026.04.01)
Tan Nguyen, M.D. is a Internal Medicine Physician provider in Garden Grove, CA (NPI 1609839299).
Provider details
- NPI number
- 1609839299
- Entity type
- Individual
- Primary specialty
- Internal Medicine PhysicianAllopathic & Osteopathic Physicians
- Credential
- M.D.
- Sex
- Male
- Sole proprietor
- No
- License
- G67119 (CA)
Specialties & taxonomies
Allopathic & Osteopathic Physicians
Profile Score
A profile completeness & documented-activity index — NOT a quality, outcomes, or patient-satisfaction rating.
- Registry tenure33% of score
20 yrs in NPPES registry
- Profile completeness33% of score
100% of core fields populated
- Practice footprint20% of score
5 documented practice locations
- Open Payments transparency13% of score
Has Open Payments disclosures (2024)
Signals a provider has no public data for (e.g. Medicare claims) are left out of the score entirely — never counted as zero — so providers without that data are not penalized. See the full formula and weights in our methodology.
What this provider prescribes (Medicare Part D)
Top drugs by Medicare Part D claim volume, 2024 · 63 distinct drugs on file.
| Drug | Part D claims (2024) | Beneficiaries |
|---|---|---|
| Atorvastatin Calcium | 181 | 35 |
| Amlodipine Besylate | 108 | 25 |
| Gabapentin | 94 | 21 |
| Metformin Hcl | 75 | 20 |
| Losartan Potassium | 66 | 16 |
| Mirtazapine | 58 | 11 |
| Metoprolol Succinate |
Transparency — industry payments
Based on CMS Open Payments, 2024; not all care is captured.
$21 across 1 record (Open Payments 2024)
Open Payments discloses payments and transfers of value (meals, travel, consulting, research, royalties) from drug and device makers to providers. This is a transparency signal, not a verdict — such payments are legal and common, and their presence is neither an endorsement nor a criticism. Source: CMS Open Payments, program year 2024.
Practice location
Mailing address
Additional practice locations (4)
- 508 S Brookhurst StAnaheim, CA 92804Phone: (800) 760-5520Fax: (800) 760-5520
- 508 S Brookhurst StAnaheim, CA 92804Phone: (800) 760-5520Fax: (800) 760-5520
- 8700 Warner Ave Ste 270Fountain Valley, CA 92708-3212Phone: (800) 560-9999Fax: (800) 391-4191
- 7514 Girard AveSuite 4La Jolla, CA 92037-5149Phone: (858) 754-1114Fax: (858) 228-9828
Registry dates
- Enumerated
- 2006-04-06
- Last updated
- 2021-07-22
- Certified
- 2021-07-22
Frequently asked questions
- What is Tan Nguyen's NPI number?
- Tan Nguyen's National Provider Identifier (NPI) is 1609839299, a unique 10-digit ID issued by CMS for use in standard healthcare transactions.
- What is Tan Nguyen's specialty?
- Tan Nguyen is listed in the NPPES registry with a primary specialty of Internal Medicine Physician (Allopathic & Osteopathic Physicians).
- Where is Tan Nguyen located?
- Tan Nguyen's practice location on file with NPPES is 12865 Main St Ste 105, Garden Grove, CA 92840-8205.
- What is Tan Nguyen's phone number?
- The practice phone number listed in the NPPES registry for Tan Nguyen is (800) 768-1977.
- Does Tan Nguyen accept Medicare?
- Tan Nguyen is approved to bill Medicare according to CMS PECOS enrollment data (2026.04.01). Confirm current participation with the provider before scheduling.
- Is Tan Nguyen's NPI active?
- Yes — Tan Nguyen's NPI (1609839299) is active in the NPPES registry as of the last update on 2021-07-22.
Source: CMS NPPES Data Dissemination (June 2026). NPI Central is not affiliated with CMS. Data is provided as-is from the public registry.