NPI registry status
Active
2026 NPPES data Internal Medicine Physician NPI 1386698660 MD
Verify on CMS → Anhtuan Nguyen, MD
Internal Medicine Physician in Westminster, California.
This profile is drawn from the federal National Provider Identifier Registry (CMS NPPES), which lists more than 7 million U.S. healthcare providers - including 172,737 in Internal Medicine Physician, and covers specialty classification, practice address, and Medicare Part D prescribing data when reported. According to CMS, every field reflects the provider's official federal registration, see our methodology.
Federal data, no proprietary rating.
We show these CMS records as-is - no composite score, no star rating, no editorial opinion layered on top.
Prescribing volume
24K
Medicare Part D claims · 627 beneficiaries · Internal Medicine Physician avg: 3K
Generic prescribing
85%
generic claims · 15% brand-name · higher generic rates reduce patient out-of-pocket costs
Industry payments
$1.2K
14 payments · CMS Open Payments (Sunshine Act)
Source: CMS Medicare Part D Prescriber Public Use File, 2023
What the federal data shows
Anhtuan Nguyen, MD filed 23,752 Medicare Part D claims in 2023 as an Internal Medicine Physician in Westminster, California, prescribing 85% generic.
- 24K
- Part D claims, 2023
- 85%
- generic prescribing
- $1.2K
- industry payments (Sunshine Act)
- ≥98th
- pct by Part D claim volume (lower-bound band)
Every figure on this page comes straight from federal CMS records (NPPES, Medicare Part D, MIPS, Open Payments) - no proprietary rating or editorial opinion is applied.
CMS NPPES provider registry desk
NPI 1386698660 · Internal Medicine Physician
NPI-10 · ENUM-LEGACY · TAX-MEGA · RX-HEAVY · BOOK-MID · PHOTO-ENUM
- NPI-10 1386698660
- ENUM-LEGACY 2006
- TAX-MEGA 173K Internal Medicine
- RX-HEAVY 24K claims
- BOOK-MID 20,046 in California
- PHOTO-ENUM Deepak Jaiswal · 2006
Anhtuan Nguyen, MD's Medicare Part D volume vs every U.S. prescriber
Total Medicare Part D claims, 2023, across all CMS prescribers nationally
23,752 ≥ 98th percentile 98% of 1,370,886 prescribers are in lower value bands
Each bar is a band; taller bars hold more prescribers. The dashed line + filled bar mark this entry. Hover or tap any bar for its full count, share, and where it sits relative to this entry.
The percentile is a conservative 100-claim band: it counts only prescribers in lower claim-volume bands. Medicare Part D claim volume is activity context, not a quality measure or recommendation. See methodology § corpus placement.
Source CMS Medicare Part D Prescriber Public Use File · 2023
◑
Board-eligible specialty (heuristic, not verified)
Anhtuan Nguyen, MD practices in an ABMS-board-eligible specialty but we don't have enough CMS-participation signals to confirm active board-certified status. Consult CertificationMatters.org (the official ABMS public lookup).
What does the federal data show about Anhtuan Nguyen, MD?
Quality data not reportedPrimary specialty
Internal Medicine Physician
Medicare Part D claims
23,752 9× vs specialty avg
Specialty distribution in California
How Internal Medicine Physician compares to other specialties among California providers
Board certification
Not published by CMS
CMS does not publish a per-provider board-certification field in NPPES. PlainDoctor does not have a reliable per-specialty certification rate to show for Internal Medicine Physician. Verify directly:
How MIPS and board certification work
The Merit-based Incentive Payment System (MIPS) scores providers 0–100 across four performance categories: Quality, Cost, Promoting Interoperability, and Improvement Activities, weighted under 42 CFR §414.1380. Reporting is voluntary for many small practices, so absence of a MIPS score is not a quality signal.
Board certification through an ABMS or AOA member board signals voluntary post-licensure examination plus continuous Maintenance of Certification cycles. Verify any individual provider's status through certificationmatters.org (ABMS) or osteopathic.org (AOA).
Practice Address
Provider Details
| NPI | 1386698660 |
|---|---|
| Specialty | Internal Medicine Physician |
| Credentials | MD |
| Gender | Male |
| NPI Issued | 05/20/2006 |
Industry payments received (2024) - CMS Open Payments transparency data
The federal Physician Payments Sunshine Act (part of the Affordable Care Act) requires drug and medical-device manufacturers + group purchasing organizations to publicly report payments and other transfers of value to physicians and teaching hospitals. The data below covers 2024 for Anhtuan Nguyen, MD. Source: openpaymentsdata.cms.gov.
Total received
$1.2K
Largest payer
Amgen Inc.
Most common payment type
Food and Beverage
Industry payments are not necessarily indicators of bias, they include research funding, consulting fees for evidence-based work, royalties for inventions, food at conferences, and similar items. The disclosure exists for transparency. Read our methodology for how we interpret this data.
License & disciplinary context - California MBC 2023 annual report
Aggregate state board data only, NOT a determination of any individual provider's status. The figures below describe statewide disciplinary activity across all ~150K California medical licensees in 2023 - they are NOT specific to Anhtuan Nguyen, MD. To verify Anhtuan Nguyen, MD's current license status, search the MBC public license lookup directly, or check the Federation of State Medical Boards (FSMB) verification service.
576
Total board actions, California 2023
Across 556 cases
3.84
Actions per 1,000 licensees
California statewide rate
probation
Most common action type
186 cases
MBC publishes annual disciplinary statistics as part of public-record reporting under each state's Administrative Procedure Act. See the full breakdown by action type and year on the California disciplinary trends page. Cross-checked against FSMB U.S. Medical Regulatory Trends.
Brand vs generic prescribing mix · Typical
Anhtuan Nguyen, MD - brand share 15.0%
Internal Medicine Physician average
15% brand-name claims vs 85% generic, on 23,752 2023 Medicare Part D claims.
The federal Medicare Part D Generic Dispensing Rate national benchmark sits near 90% generic / 10% brand for primary-care prescribers, per CMS Office of the Actuary 2024 estimates. Higher brand share is common in specialty prescribing where generic equivalents are not available.
Medicare Part D Prescribing Data
CMS Medicare Part D prescriber-level data for calendar year 2023.
23,752
Total Claims
$3.1M
Total Drug Cost
627
Medicare Beneficiaries
Prescribing Breakdown
- 30-Day Fills
- 44,268
- Total Day Supply
- 1,300,986
- Brand vs Generic
- 15% brand / 85% generic
- Brand Drug Cost
- $2.2M
- Generic Drug Cost
- $950K
- Opioid Claims
- 25 (0.1% rate)
- Antibiotic Claims
- 244
Patient Demographics
- Average Patient Age
- 73.0 years
- Avg HCC Risk Score
- 1.07
- Gender Split
- 53% female / 47% male
- Age Distribution
- <65: 23, 65-74: 368, 75-84: 192, 85+: 44
Top Prescribed Drugs (Medicare Part D)
Top drugs by claim count for calendar year 2023. Based on Medicare Part D data only.
What Anhtuan Nguyen, MD prescribes most
Top Medicare Part D drugs by claim count, 2023
- Rosuvastatin Calcium
Rosuvastatin Calcium
1,224 claims
- Celecoxib
Celecoxib
736 claims
- Amlodipine Besylate
Amlodipine Besylate
670 claims
- Pioglitazone Hcl
Pioglitazone Hcl
653 claims
- Vascepa
Vascepa
648 claims
- Fluticasone Propio…
Fluticasone Propionate
640 claims
- Metformin Hcl Er
Metformin Hcl Er
607 claims
- Jardiance
Jardiance
603 claims
| Drug | Claims |
|---|---|
| Rosuvastatin Calcium | 1,224 |
| Celecoxib | 736 |
| Amlodipine Besylate | 670 |
| Pioglitazone Hcl | 653 |
| Vascepa Icosapent Ethyl | 648 |
| Fluticasone Propionate | 640 |
| Metformin Hcl Er Metformin Hcl | 607 |
| Jardiance Empagliflozin | 603 |
| Levocetirizine Dihydrochloride | 581 |
| Atorvastatin Calcium | 543 |
* Counts below 11 are suppressed by CMS for patient privacy. Generic names shown where available from CMS Part D data.
Internal Medicine Physician Overview
How Anhtuan Nguyen, MD fits within the Internal Medicine Physician landscape nationally.
172,737
Internal Medicine Physician Providers in US
56
States with Internal Medicine Physician
2,716
Avg Claims per Provider
Anhtuan Nguyen, MD's 23,752 claims are above the specialty average of 2,716.
Nationwide Internal Medicine Physician peers with similar MIPS or enrollment year
Two federal-record peer sets for Nguyen, both outside California so the neighborhoods are not geographic containment.
Same NPPES enumeration year (2006)
Same-specialty clinicians who entered the NPI registry in the same calendar year, outside this state.
Nearby Internal Medicine Physician Providers in California
Other clinicians with the same primary specialty enrolled in California, drawn from the same CMS NPPES roster as Nguyen.
One of 20,046 Internal Medicine Physician providers enrolled in California, 5 are shown here.
Dr. Jacob Aaron
MD
San Francisco, CA
Dr. Alistair Aaronson
MD
Stanford, CA
Dr. Jose Abad.
MD
Sacramento, CA
Dr. Donna Abare
MD
Oakland, CA
Marce Abare
Scotts Valley, CA
Compare Internal Medicine Physician nationally: see state-by-state distribution →
Frequently Asked Questions
What is Anhtuan Nguyen, MD's specialty? ▼
Anhtuan Nguyen, MD specializes in Internal Medicine Physician and practices in Westminster, California. Credentials: MD.
How much does Anhtuan Nguyen, MD prescribe under Medicare Part D? ▼
In 2023, Anhtuan Nguyen, MD wrote 23,752 Medicare Part D claims totaling $3.1M in drug costs for 627 beneficiaries.
Where is Anhtuan Nguyen, MD located? ▼
Anhtuan Nguyen, MD is located at 14541 BROOKHURST ST, Westminster, CA, 92683. Phone: (714) 531-2000.
What is Anhtuan Nguyen, MD's NPI number? ▼
Anhtuan Nguyen, MD's National Provider Identifier (NPI) is 1386698660, issued on 05/20/2006.
Does Anhtuan Nguyen, MD prescribe more brand-name or generic drugs? ▼
Anhtuan Nguyen, MD's prescribing is 15% brand-name and 85% generic drugs by claim count, with $2.2M in brand drug costs.
Does Anhtuan Nguyen, MD prescribe opioids? ▼
Yes, Anhtuan Nguyen, MD had 25 opioid claims in 2023 with an opioid prescribing rate of 0.1%.
How many Internal Medicine Physician providers are there in the US? ▼
There are 172,737 Internal Medicine Physician providers across 56 states in the US. The average Internal Medicine Physician provider writes 2,716 Medicare Part D claims per year.
What drugs does Anhtuan Nguyen, MD prescribe most often? ▼
Based on 2023 Medicare Part D data, Anhtuan Nguyen, MD's most frequently prescribed drugs include Rosuvastatin Calcium, Celecoxib, Amlodipine Besylate. This reflects Medicare Part D prescriptions only and does not include commercial insurance or other payer types.
Does Anhtuan Nguyen, MD accept Medicare? ▼
Anhtuan Nguyen, MD appears in CMS Medicare data with 23,752 Part D claims and 627 Medicare beneficiaries in 2023. Contact the provider's office directly to confirm current Medicare enrollment and accepted plans.
How can I verify Anhtuan Nguyen, MD's credentials? ▼
Anhtuan Nguyen, MD's NPI is 1386698660 with credentials MD. You can verify this through the NPPES NPI Registry, check state medical board records, and confirm board certification through the ABMS or AOA.
Data Sources
View source datasets and methodology notes
- Provider Directory
- CMS National Plan and Provider Enumeration System (NPPES), download.cms.gov/nppes, updated monthly. Contains NPI, specialty, credentials, and practice location.
- Specialty Classification
- NUCC Health Care Provider Taxonomy (nucc.org), the industry standard for classifying provider specialties in Medicare and Medicaid billing.
- Prescribing Data
- CMS Medicare Part D Prescriber Public Use File (2023). Includes claims, drug costs, beneficiaries, and opioid prescribing rates.
- Limitations
- Provider data is self-reported to CMS. Prescribing data reflects Medicare Part D only and does not include commercial insurance, Medicaid, or cash prescriptions. Claims below 11 beneficiaries are suppressed by CMS for privacy.
See our complete data methodology for details on how we collect and process government data.
Data as of April 2026 (NPPES) / 2023 (Medicare Part D). Source: Centers for Medicare & Medicaid Services (CMS).
Disclaimer: Data from CMS NPPES and Medicare Part D. PlainDoctor does not rate or rank providers. Provider information is self-reported and may not be current. Always verify information directly with the provider. About · Methodology
Every figure on PlainDoctor is rendered directly from the federal CMS NPPES registry, Medicare Part D, MIPS, and Open Payments records, no number is typed in by an editor. See our editorial standards & corrections policy, the methodology behind these numbers, or report a data error. Data current as of May 2026.