NPI registry status
Active
2026 NPPES data Gynecology Physician NPI 1588725659 M.D.
Verify on CMS → Duong Phung, M.D.
Gynecology Physician in Chino, 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 3,912 in Gynecology 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
95
Medicare Part D claims · 31 beneficiaries · Gynecology Physician avg: 319
Generic prescribing
78%
generic claims · 22% brand-name · higher generic rates reduce patient out-of-pocket costs
Industry payments
$354.75
4 payments · CMS Open Payments (Sunshine Act)
Source: CMS Medicare Part D Prescriber Public Use File, 2024
What the federal data shows
Duong Phung, M.D. filed 95 Medicare Part D claims in 2024 as a Gynecology Physician in Chino, California, prescribing 78% generic.
- 95
- Part D claims, 2024
- 78%
- generic prescribing
- $354.75
- industry payments (Sunshine Act)
- ≥0th
- 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.
Federal trust snapshot
What official records show about Duong Phung, M.D.
Federal records show an active NPI with Medicare Part D prescribing activity — verifiable registry data, not a proprietary rating.
- Verified
NPI registry status
Active listing in the CMS National Provider Identifier Registry (NPI 1588725659), first enumerated 12/13/2006.
Source: CMS NPPES
- Reported
Medicare Part D participation
Filed 95 Medicare Part D prescription claims in the 2023 CMS public use file — indicates active Medicare prescribing participation.
Source: CMS Part D Prescriber PUF
- Reported
Board certification signal
Practices in an ABMS-board-eligible specialty; board certification not confirmed in federal records.
- Reported
Industry payment transparency
$354.75 in reported industry payments (4 transfers) in 2024 under the federal Sunshine Act — disclosed transfers of value, not a quality rating.
Source: CMS Open Payments
- State context
State board disciplinary context
California statewide board action statistics are published annually — these figures describe aggregate state activity, not Duong Phung, M.D.'s individual license status. Verify directly with the state medical board.
Source: Medical Board of California annual report FY 2022-23
- Not in federal data
Individual sanction lookup
PlainDoctor does not publish per-provider disciplinary determinations. Confirm current license and any individual actions through the state medical board or FSMB verification service.
Source: State medical board / FSMB
This trust snapshot summarizes only what appears in federal CMS/NPPES public records. It is not a composite score, star rating, patient review, or clinical recommendation. PlainDoctor never fabricates reviews or AggregateRating schema.
Compare Phung with other Gynecology Physician providers
Same primary specialty, same federal CMS NPPES roster.
Also enrolled in California
- Dr. Ahmed Abdelaziz, MD Santa Maria, CA
- Dr. Keevan Abramson, MD Fort Bragg, CA
- Dr. Robert Adams, MD Monterey, CA
- Dr. Naphthali Alinsod, M.D. Laguna Beach, CA
- Dr. Parichehr Allameh, M.D. Sylmar, CA
- Dr. Margarita Alvarado, M.D. San Francisco, CA
Other specialties in Chino: Student in an Organized Health Care Education/Training Program (76) · Marriage & Family Therapist (71) · Pharmacist (69) · General Practice Dentistry (53)
CMS NPPES provider registry desk
NPI 1588725659 · Gynecology Physician
NPI-10 · ENUM-LEGACY · TAX-NARROW · RX-TRACE · BOOK-THIN · PHOTO-ENUM
- NPI-10 1588725659
- ENUM-LEGACY 2006
- TAX-NARROW 3,912
- RX-TRACE 95
- BOOK-THIN 377 in California
- PHOTO-ENUM Marshall White, MD · 2006
Duong Phung, M.D.'s Medicare Part D volume vs every U.S. prescriber
Total Medicare Part D claims, 2024, across all CMS prescribers nationally
95 ≥ 0th percentile 0% of 1,416,883 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 · 2024
◑
Board-eligible specialty (heuristic, not verified)
Duong Phung, M.D. 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 Duong Phung, M.D.?
Quality data not reportedPrimary specialty
Gynecology Physician
Medicare Part D claims
95 70% vs specialty avg
Specialty distribution in California
How Gynecology 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 Gynecology 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 | 1588725659 |
|---|---|
| Specialty | Gynecology Physician |
| Credentials | M.D. |
| Gender | Male |
| NPI Issued | 12/13/2006 |
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 Duong Phung, M.D.. Source: openpaymentsdata.cms.gov.
Total received
$355
Largest payer
Gilead Sciences, 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 Medical Board of California, FY 2022-23
Aggregate state board data only, NOT a determination of any individual provider's status. The figures below describe statewide disciplinary activity across 148,769 California physician licenses in effect in FY 2022-23 - they are NOT specific to Duong Phung, M.D.. To verify Duong Phung, M.D.'s current license status, use the state board's own license search (see California license lookup), or the Federation of State Medical Boards (FSMB) verification service.
374
Administrative board actions, California FY 2022-23
2.51
Actions per 1,000 physician licenses in effect
California statewide rate
Probation
Most common action type
148 actions
Source: Medical Board of California Annual Report 2022-2023, page 18 (licenses in effect: page 12). Full breakdown by action type on the California discipline page.
Brand vs generic prescribing mix · Typical
Duong Phung, M.D. - brand share 22.0%
Gynecology Physician average
22% brand-name claims vs 78% generic, on 95 2024 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 2024.
95
Total Claims
$15K
Total Drug Cost
31
Medicare Beneficiaries
Prescribing Breakdown
- 30-Day Fills
- 166.733
- Total Day Supply
- 4,418
- Brand vs Generic
- 22% brand / 78% generic
- Brand Drug Cost
- $12K
- Generic Drug Cost
- $3K
- Antibiotic Claims
- 11
Patient Demographics
- Average Patient Age
- 69.1 years
- Avg HCC Risk Score
- 1.31
Top Prescribed Drugs (Medicare Part D)
Top drugs by claim count for calendar year 2024. Based on Medicare Part D data only.
| Drug | Claims |
|---|---|
| Estradiol | 16 |
| Medroxyprogesterone Acetate | 12 |
* Counts below 11 are suppressed by CMS for patient privacy. Generic names shown where available from CMS Part D data.
Gynecology Physician Overview
How Duong Phung, M.D. fits within the Gynecology Physician landscape nationally.
3,912
Gynecology Physician Providers in US
53
States with Gynecology Physician
319
Avg Claims per Provider
Duong Phung, M.D.'s 95 claims are below the specialty average of 319.
Nationwide Gynecology Physician peers with similar MIPS or enrollment year
Two federal-record peer sets for Phung, 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 Gynecology Physician Providers in California
Other clinicians with the same primary specialty enrolled in California, drawn from the same CMS NPPES roster as Phung.
One of 377 Gynecology Physician providers enrolled in California, 11 are shown on this page.
Dr. Michal Amir
M.D.
Beverly Hills, CA
Dr. Malaika Amneus
M.D.
Sylmar, CA
Dr. Anna Anderson
MD
Mountain View, CA
Dr. Donald Armstrong
M.D.
Fullerton, CA
Dr. John Armstrong
MD
Napa, CA
Compare Gynecology Physician nationally: see state-by-state distribution →
Frequently Asked Questions
What is Duong Phung, M.D.'s specialty? ▼
Duong Phung, M.D. specializes in Gynecology Physician and practices in Chino, California. Credentials: M.D..
How much does Duong Phung, M.D. prescribe under Medicare Part D? ▼
In 2024, Duong Phung, M.D. wrote 95 Medicare Part D claims totaling $15K in drug costs for 31 beneficiaries.
Where is Duong Phung, M.D. located? ▼
Duong Phung, M.D. is located at 5365 WALNUT AVE, Chino, CA, 91710. Phone: (909) 620-1885.
What is Duong Phung, M.D.'s NPI number? ▼
Duong Phung, M.D.'s National Provider Identifier (NPI) is 1588725659, issued on 12/13/2006.
Does Duong Phung, M.D. prescribe more brand-name or generic drugs? ▼
Duong Phung, M.D.'s prescribing is 22% brand-name and 78% generic drugs by claim count, with $12K in brand drug costs.
How many Gynecology Physician providers are there in the US? ▼
There are 3,912 Gynecology Physician providers across 53 states in the US. The average Gynecology Physician provider writes 319 Medicare Part D claims per year.
What drugs does Duong Phung, M.D. prescribe most often? ▼
Based on 2024 Medicare Part D data, Duong Phung, M.D.'s most frequently prescribed drugs include Estradiol, Medroxyprogesterone Acetate. This reflects Medicare Part D prescriptions only and does not include commercial insurance or other payer types.
Does Duong Phung, M.D. accept Medicare? ▼
Duong Phung, M.D. appears in CMS Medicare data with 95 Part D claims and 31 Medicare beneficiaries in 2024. Contact the provider's office directly to confirm current Medicare enrollment and accepted plans.
How can I verify Duong Phung, M.D.'s credentials? ▼
Duong Phung, M.D.'s NPI is 1588725659 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
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 (2024). 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 August 2026 (NPPES) / 2024 (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 September 2026.