2026 NPPES data Hematology (Internal Medicine) Physician NPI 1528083664 M.D.
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HOA NGUYEN, M.D.

Hematology (Internal Medicine) Physician in MARYSVILLE, California. CMS National Plan and Provider Enumeration System profile including specialty classification, practice address, and Medicare prescribing data when reported.

Federal data — no proprietary rating. PlainDoctor publishes the actual CMS NPPES and Medicare records — NPI registration, specialty, practice location, and prescribing data — without a composite score or editorial opinion on top. Every field traces to a federal source.
Prescribing volume
573
Medicare Part D claims · 134 beneficiaries · Hematology (Internal Medicine) Physician avg: 693
MIPS score
90.928/100
▲ 8 pts above national avg 83.1 · [object Object]
Industry payments
$151.65
3 payments · CMS Open Payments (Sunshine Act)

What the federal data shows

HOA NGUYEN, M.D. reported a CMS MIPS final score of 90.928/100 — above the 83.1 national average — and filed 573 Medicare Part D claims in 2023.

90.928/100
MIPS score · +8 vs avg
573
Part D claims, 2023
Likely
board-certified (heuristic)

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.

HOA NGUYEN, M.D.'s MIPS score vs every scored U.S. clinician

CMS Merit-based Incentive Payment System (MIPS) final score, 2023 — the federal quality measure

91 Top 40% higher than 60% of 477,587 scored providers

0–10: 8,684 scored providers (2%). Below this entry. 10–20: 3,008 scored providers (1%). Below this entry. 20–30: 3,069 scored providers (1%). Below this entry. 30–40: 2,746 scored providers (1%). Below this entry. 40–50: 2,928 scored providers (1%). Below this entry. 50–60: 5,882 scored providers (1%). Below this entry. 60–70: 13,906 scored providers (3%). Below this entry. 70–80: 118,074 scored providers (25%). Below this entry. 80–90: 129,887 scored providers (27%). Below this entry. 90–100: 189,403 scored providers (40%). This entry sits in this band. This provider 0 100 every MIPS-scored clinician, bucketed by value

Each bar is a band; taller bars hold more scored providers. 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.

Source CMS Merit-based Incentive Payment System (MIPS) · 2023

Board certification likely (heuristic — not verified)

HOA NGUYEN, M.D. practices in an ABMS-board-eligible specialty and shows active CMS Medicare participation + MIPS quality reporting + 1 hospital affiliation — signals consistent with board-certified status. For verified board certification, see CertificationMatters.org (the official ABMS public lookup).

What does the federal data show about HOA NGUYEN, M.D.?

High performer (top quartile)

NPI registry status

Active

Issued 07/12/2006

NPI 1528083664

Primary specialty

Hematology (Internal Medicine) Physician

Niche

1,436 US NPIs in this specialty

Medicare Part D claims

573 17% vs specialty avg

2023 prescription claims

Specialty avg: 693

MIPS final score

90.928/100 7.828000000000003% pts

Exceptional band

vs 83.1 national avg

Specialty distribution in California

How Hematology (Internal Medicine) Physician compares to other specialties among California providers

California providers

Hematology (Internal Medicine) Physician share within California

1. Hematology (Internal Medicine) Physician42%2. Internal medicine21%3. Family medicine17%4. Surgical12%5. Pediatric8%
Hematology (Internal Medicine) Physician share within California

Medicare quality performance — MIPS

HOA NGUYEN, M.D.'s 2023 MIPS final score plotted against the Hematology (Internal Medicine) Physician national average

High performer (top quartile)
MIPS Final Score
90.928/100
vs 83.1 national avg · 2023 performance year

MIPS final score (Hematology (Internal Medicine) Physician) — 90.928/100 vs national avg 83.1

0%100%National avg83%90.9%
MIPS final score (Hematology (Internal Medicine) Physician) — 90.928/100 vs national avg 83.1

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).

HOA NGUYEN, M.D. appears in the CMS NPPES registry as a Hematology (Internal Medicine) Physician provider holding M.D. credentials at 618 5TH ST, MARYSVILLE, CA, 95901, with a listed phone of (530) 749-4400. NPI 1528083664 was issued on 07/12/2006. Because NPPES data is self-reported by the provider and refreshed monthly, the address, phone, and specialty reflect what NGUYEN most recently submitted to CMS rather than a vetted directory listing, which is why patients should always confirm the practice is still at this location before scheduling.

Medicare Part D records for calendar year 2023 show 573 prescription claims written by this provider, covering 134 Medicare beneficiaries and totaling roughly $1.4 million in drug spend, with an opioid prescribing rate of 6.5%. These figures capture only Medicare Part D — commercial insurance, Medicaid, and cash-pay prescriptions are not included, and any drug-beneficiary cell under 11 is suppressed by CMS for patient privacy. On the CMS Merit-based Incentive Payment System, this provider earned a Final Score of 90.928/100 for the 2023 performance year (Quality 63.354), compared with the national average of 83.1.

Hematology (Internal Medicine) Physician is a narrow specialty nationwide, with 1,436 enrolled providers across 50 states and an average of 693 Part D claims per prescriber, so the context for interpreting these metrics differs meaningfully from a primary-care baseline. Important: PlainDoctor is a directory of publicly available government data, not medical advice, a malpractice database, or a quality rating. Inclusion here does not imply a recommendation, and absence of complaints or sanctions on this page does not mean none exist — always verify credentials through the NPPES NPI Registry, your state medical board, and the ABMS or AOA before making healthcare decisions.

Practice Address

618 5TH ST
MARYSVILLE, CA 95901

Provider Details

NPI 1528083664
Specialty Hematology (Internal Medicine) Physician
Credentials M.D.
Gender Male
NPI Issued 07/12/2006

CMS Quality Score (MIPS)

Merit-based Incentive Payment System (MIPS) scores from CMS, 2023 performance year.

90.928
Final Score
Avg: 83.1
63.354
Quality
100
Promoting Interoperability

Reporting: Alternative Payment Model

Hospital and facility affiliations

Facilities where HOA NGUYEN, M.D. bills Medicare from. Star ratings (1-5) are CMS Hospital Compare's "Hospital overall rating" — a composite of mortality, readmission, patient experience, safety, timely care, and efficient use of medical imaging measures. Source: CMS Care Compare.

REGENTS OF THE UNIVERSITY OF CALIFORNIA
MARYSVILLE, CA

Affiliations sourced from CMS Doctors and Clinicians National Downloadable File; hospital ratings from CMS Hospital General Information dataset (cross-referenced by facility name + state).

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 HOA NGUYEN, M.D.. Source: openpaymentsdata.cms.gov.

Total received

$152

Largest payer

Teleflex LLC

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 HOA NGUYEN, M.D.. To verify HOA NGUYEN, M.D.'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.

Medicare Part D Prescribing Data

CMS Medicare Part D prescriber-level data for calendar year 2023.

573
Total Claims
$1.4M
Total Drug Cost
134
Medicare Beneficiaries

Prescribing Breakdown

30-Day Fills
808
Total Day Supply
21,194
Generic Drug Cost
$51K
Opioid Claims
37 (6.5% rate)

Patient Demographics

Average Patient Age
73.6 years
Avg HCC Risk Score
1.89
Gender Split
65% female / 35% male
Age Distribution
<65: 12, 65-74: 58, 75-84: 51, 85+: 13

Top Prescribed Drugs (Medicare Part D)

Top drugs by claim count for calendar year 2023. Based on Medicare Part D data only.

What HOA NGUYEN, M.D. prescribes most

Top Medicare Part D drugs by claim count, 2023

claims
Source CMS Medicare Part D Prescriber Public Use File As of 2023
Drug Claims
Ondansetron Hcl
77
Anastrozole
62
Promethazine Hcl
40
Letrozole
31
Revlimid
Lenalidomide
24
Hydrocodone-Acetaminophen
Hydrocodone/Acetaminophen
21
Dexamethasone
20
Eliquis
Apixaban
17
Naloxone Hcl
17
Allopurinol
15

* Counts below 11 are suppressed by CMS for patient privacy. Generic names shown where available from CMS Part D data.

Hematology (Internal Medicine) Physician Overview

How HOA NGUYEN, M.D. fits within the Hematology (Internal Medicine) Physician landscape nationally.

1,436
Hematology (Internal Medicine) Physician Providers in US
50
States with Hematology (Internal Medicine) Physician
693
Avg Claims per Provider

HOA NGUYEN, M.D.'s 573 claims are below the specialty average of 693.

Nearby Hematology (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.

Compare Hematology (Internal Medicine) Physician nationally: see state-by-state distribution →

Frequently Asked Questions

What is HOA NGUYEN, M.D.'s specialty?
HOA NGUYEN, M.D. specializes in Hematology (Internal Medicine) Physician and practices in MARYSVILLE, California. Credentials: M.D..
How much does HOA NGUYEN, M.D. prescribe under Medicare Part D?
In 2023, HOA NGUYEN, M.D. wrote 573 Medicare Part D claims totaling $1.4M in drug costs for 134 beneficiaries.
What is HOA NGUYEN, M.D.'s Medicare quality score?
HOA NGUYEN, M.D. has a CMS MIPS Final Score of 90.928/100 (Quality: 63.354). The national average MIPS Final Score is 83.1. Source: CMS Merit-based Incentive Payment System (MIPS) 2023.
Where is HOA NGUYEN, M.D. located?
HOA NGUYEN, M.D. is located at 618 5TH ST, MARYSVILLE, CA, 95901. Phone: (530) 749-4400.
What is HOA NGUYEN, M.D.'s NPI number?
HOA NGUYEN, M.D.'s National Provider Identifier (NPI) is 1528083664, issued on 07/12/2006.
Does HOA NGUYEN, M.D. prescribe opioids?
Yes, HOA NGUYEN, M.D. had 37 opioid claims in 2023 with an opioid prescribing rate of 6.5%.
How many Hematology (Internal Medicine) Physician providers are there in the US?
There are 1,436 Hematology (Internal Medicine) Physician providers across 50 states in the US. The average Hematology (Internal Medicine) Physician provider writes 693 Medicare Part D claims per year.
What drugs does HOA NGUYEN, M.D. prescribe most often?
Based on 2023 Medicare Part D data, HOA NGUYEN, M.D.'s most frequently prescribed drugs include Ondansetron Hcl, Anastrozole, Promethazine Hcl. This reflects Medicare Part D prescriptions only and does not include commercial insurance or other payer types.
Does HOA NGUYEN, M.D. accept Medicare?
HOA NGUYEN, M.D. appears in CMS Medicare data with 573 Part D claims and 134 Medicare beneficiaries in 2023. Contact the provider's office directly to confirm current Medicare enrollment and accepted plans.
How can I verify HOA NGUYEN, M.D.'s credentials?
HOA NGUYEN, M.D.'s NPI is 1528083664 with credentials M.D.. 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

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.
Quality Performance
CMS Merit-based Incentive Payment System (MIPS) — 2023 performance year.
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