NPI registry status
Active
2026 NPPES data Specialist NPI 1285216739 MD
Verify on CMS → Corey Ngoy, MD
Specialist in Norwalk, 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 69,608 in Specialist, 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
122
Medicare Part D claims · Specialist avg: 1K
What the federal data shows
Corey Ngoy, MD filed 122 Medicare Part D claims in 2023 as a Specialist in Norwalk, California.
- 122
- Part D claims, 2023
- ≥35th
- 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 1285216739 · Specialist
NPI-10 · ENUM-RECENT · TAX-MEGA · RX-LIGHT · BOOK-MID · PHOTO-ENUM
- NPI-10 1285216739
- ENUM-RECENT 2021
- TAX-MEGA 70K Specialist
- RX-LIGHT 122
- BOOK-MID 6,672 in California
- PHOTO-ENUM Takai Hose · 2021
Corey Ngoy, MD's Medicare Part D volume vs every U.S. prescriber
Total Medicare Part D claims, 2023, across all CMS prescribers nationally
122 ≥ 35th percentile 35% 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
What does the federal data show about Corey Ngoy, MD?
Quality data not reportedPrimary specialty
Specialist
Medicare Part D claims
122 92% vs specialty avg
Specialty distribution in California
How Specialist 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 Specialist. 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 | 1285216739 |
|---|---|
| Specialty | Specialist |
| Credentials | MD |
| Gender | Male |
| NPI Issued | 04/24/2021 |
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 Corey Ngoy, MD. To verify Corey Ngoy, 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.
Medicare Part D Prescribing Data
CMS Medicare Part D prescriber-level data for calendar year 2023.
122
Total Claims
$8K
Total Drug Cost
N/A
Medicare Beneficiaries
Prescribing Breakdown
- 30-Day Fills
- 128
- Total Day Supply
- 3,790
- Generic Drug Cost
- $8K
Patient Demographics
- Average Patient Age
- 54.9 years
- Avg HCC Risk Score
- 1.71
Top Prescribed Drugs (Medicare Part D)
Top drugs by claim count for calendar year 2023. Based on Medicare Part D data only.
What Corey Ngoy, MD prescribes most
Top Medicare Part D drugs by claim count, 2023
- Clozapine
Clozapine
26 claims
- Olanzapine
Olanzapine
13 claims
- Haloperidol
Haloperidol
12 claims
- Ziprasidone Hcl
Ziprasidone Hcl
11 claims
| Drug | Claims |
|---|---|
| Clozapine | 26 |
| Olanzapine | 13 |
| Haloperidol | 12 |
| Ziprasidone Hcl | 11 |
* Counts below 11 are suppressed by CMS for patient privacy. Generic names shown where available from CMS Part D data.
Specialist Overview
How Corey Ngoy, MD fits within the Specialist landscape nationally.
69,608
Specialist Providers in US
55
States with Specialist
1,474
Avg Claims per Provider
Corey Ngoy, MD's 122 claims are below the specialty average of 1,474.
Nationwide Specialist peers with similar MIPS or enrollment year
Two federal-record peer sets for Ngoy, both outside California so the neighborhoods are not geographic containment.
Same NPPES enumeration year (2021)
Same-specialty clinicians who entered the NPI registry in the same calendar year, outside this state.
Nearby Specialist Providers in California
Other clinicians with the same primary specialty enrolled in California, drawn from the same CMS NPPES roster as Ngoy.
One of 6,672 Specialist providers enrolled in California, 5 are shown here.
Adrienne Abad Santos
San Francisco, CA
Dr. Brenda Abarca
MD
Torrance, CA
Dr. Fatemeh Abbasi
PT
Van Nuys, CA
Dr. Erlinda Abcede
M.D.
Cudahy, CA
Dr. Maher Abdallah
M.D.
Palm Springs, CA
Compare Specialist nationally: see state-by-state distribution →
Frequently Asked Questions
What is Corey Ngoy, MD's specialty? ▼
Corey Ngoy, MD specializes in Specialist and practices in Norwalk, California. Credentials: MD.
How much does Corey Ngoy, MD prescribe under Medicare Part D? ▼
In 2023, Corey Ngoy, MD wrote 122 Medicare Part D claims totaling $8K in drug costs for N/A beneficiaries.
Where is Corey Ngoy, MD located? ▼
Corey Ngoy, MD is located at 11401 BLOOMFIELD AVE, Norwalk, CA, 90650. Phone: (562) 863-7011.
What is Corey Ngoy, MD's NPI number? ▼
Corey Ngoy, MD's National Provider Identifier (NPI) is 1285216739, issued on 04/24/2021.
How many Specialist providers are there in the US? ▼
There are 69,608 Specialist providers across 55 states in the US. The average Specialist provider writes 1,474 Medicare Part D claims per year.
What drugs does Corey Ngoy, MD prescribe most often? ▼
Based on 2023 Medicare Part D data, Corey Ngoy, MD's most frequently prescribed drugs include Clozapine, Olanzapine, Haloperidol. This reflects Medicare Part D prescriptions only and does not include commercial insurance or other payer types.
Does Corey Ngoy, MD accept Medicare? ▼
Corey Ngoy, MD appears in CMS Medicare data with 122 Part D claims and N/A Medicare beneficiaries in 2023. Contact the provider's office directly to confirm current Medicare enrollment and accepted plans.
How can I verify Corey Ngoy, MD's credentials? ▼
Corey Ngoy, MD's NPI is 1285216739 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.