NPI registry status
Active
2026 NPPES data Internal Medicine Physician NPI 1508805839 M.D.
Verify on CMS → Hai Sun Park, M.D.
Internal Medicine Physician in Englewood Cliffs, New Jersey.
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
4K
Medicare Part D claims · 316 beneficiaries · Internal Medicine Physician avg: 3K
Generic prescribing
82%
generic claims · 17% brand-name · higher generic rates reduce patient out-of-pocket costs
Industry payments
$967.65
50 payments · CMS Open Payments (Sunshine Act)
Source: CMS Medicare Part D Prescriber Public Use File, 2023
What the federal data shows
Hai Sun Park, M.D. filed 4,333 Medicare Part D claims in 2023 as an Internal Medicine Physician in Englewood Cliffs, New Jersey, prescribing 82% generic.
- 4K
- Part D claims, 2023
- 82%
- generic prescribing
- $967.65
- industry payments (Sunshine Act)
- ≥92nd
- 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.
Hai Sun Park, M.D.'s Medicare Part D volume vs every U.S. prescriber
Total Medicare Part D claims, 2023, across all CMS prescribers nationally
4,333 ≥ 92nd percentile 92% 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
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Board-eligible specialty (heuristic, not verified)
Hai Sun Park, 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 Hai Sun Park, M.D.?
Quality data not reportedPrimary specialty
Internal Medicine Physician
Medicare Part D claims
4,333 60% vs specialty avg
Specialty distribution in New Jersey
How Internal Medicine Physician compares to other specialties among New Jersey 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).
Hai Sun Park, M.D. appears in the CMS NPPES registry as an Internal Medicine Physician provider holding M.D. credentials at 464 HUDSON TER STE 200, Englewood Cliffs, NJ, 07632, with a listed phone of (201) 408-5442. NPI 1508805839 was issued on 06/05/2006.
Medicare Part D records for calendar year 2023 show 4,333 prescription claims written by this provider, covering 316 Medicare beneficiaries and totaling roughly $2.4 million in drug spend, split 17% brand-name and 82% generic by claim count, with an opioid prescribing rate of 1.0%.
Internal Medicine Physician is a high-volume specialty nationwide, with 172,737 enrolled providers across 56 states and an average of 2,716 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
Provider Details
| NPI | 1508805839 |
|---|---|
| Specialty | Internal Medicine Physician |
| Credentials | M.D. |
| Gender | Female |
| NPI Issued | 06/05/2006 |
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 Hai Sun Park, M.D.. Source: openpaymentsdata.cms.gov.
Total received
$968
Largest payer
Janssen Biotech, 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.
Brand vs generic prescribing mix · Typical
Hai Sun Park, M.D. - brand share 17.0%
Internal Medicine Physician average
17% brand-name claims vs 82% generic, on 4,333 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.
4,333
Total Claims
$2.4M
Total Drug Cost
316
Medicare Beneficiaries
Prescribing Breakdown
- 30-Day Fills
- 8,502
- Total Day Supply
- 250,605
- Brand vs Generic
- 17% brand / 82% generic
- Brand Drug Cost
- $2.2M
- Generic Drug Cost
- $256K
- Opioid Claims
- 45 (1.0% rate)
- Antibiotic Claims
- 66
Patient Demographics
- Average Patient Age
- 76.1 years
- Avg HCC Risk Score
- 1.22
- Gender Split
- 64% female / 36% male
Top Prescribed Drugs (Medicare Part D)
Top drugs by claim count for calendar year 2023. Based on Medicare Part D data only.
What Hai Sun Park, M.D. prescribes most
Top Medicare Part D drugs by claim count, 2023
- Atorvastatin Calcium
Atorvastatin Calcium
423 claims
- Amlodipine Besylate
Amlodipine Besylate
317 claims
- Losartan Potassium
Losartan Potassium
242 claims
- Metformin Hcl 160
Metformin Hcl
160 claims
- Vascepa 128
Vascepa
128 claims
- Simvastatin 112
Simvastatin
112 claims
- Levothyroxine Sodium 94
Levothyroxine Sodium
94 claims
- Lisinopril 88
Lisinopril
88 claims
| Drug | Claims |
|---|---|
| Atorvastatin Calcium | 423 |
| Amlodipine Besylate | 317 |
| Losartan Potassium | 242 |
| Metformin Hcl | 160 |
| Vascepa Icosapent Ethyl | 128 |
| Simvastatin | 112 |
| Levothyroxine Sodium | 94 |
| Lisinopril | 88 |
| Metoprolol Succinate | 88 |
| Creon Lipase/Protease/Amylase | 83 |
* 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 Hai Sun Park, M.D. 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
Hai Sun Park, M.D.'s 4,333 claims are above the specialty average of 2,716.
Nearby Internal Medicine Physician Providers in New Jersey
Other clinicians with the same primary specialty enrolled in New Jersey, drawn from the same CMS NPPES roster as Park.
Dr. Joseph Aaron
MD, FACP
Short Hills, NJ
Dr. Sirike Aasmaa
DO
Montville, NJ
Dr. Holly Abate Bersalona
M.D.
Sea Girt, NJ
Dr. Kaniz Zehra Abbas
MD
Trenton, NJ
Dr. Shahida Abbas
MD
Old Bridge, NJ
Compare Internal Medicine Physician nationally: see state-by-state distribution →
Before you book an appointment
Use this federal record as your verification checklist, not as a recommendation.
- Confirm the NPI record is current in the official CMS registry, providers update their own NPPES details, and moves can lag. Verify this NPI
- Check the active license and any disciplinary history with the New Jersey medical board, federal registration is not a license check. Credential verification guide
- Weigh a second option: compare this provider with a nearby Internal Medicine Physician peer on Medicare volume and prescribing patterns. Compare providers
Medicare Part D and MIPS figures describe practice patterns in federal programs only, they are not quality ratings, and PlainDoctor does not rate, rank, or recommend providers.
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Medical Specialties Explained
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Understanding Medicare Claims Data
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How insurance networks affect your costs
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Frequently Asked Questions
What is Hai Sun Park, M.D.'s specialty? ▼
Hai Sun Park, M.D. specializes in Internal Medicine Physician and practices in Englewood Cliffs, New Jersey. Credentials: M.D..
How much does Hai Sun Park, M.D. prescribe under Medicare Part D? ▼
In 2023, Hai Sun Park, M.D. wrote 4,333 Medicare Part D claims totaling $2.4M in drug costs for 316 beneficiaries.
Where is Hai Sun Park, M.D. located? ▼
Hai Sun Park, M.D. is located at 464 HUDSON TER STE 200, Englewood Cliffs, NJ, 07632. Phone: (201) 408-5442.
What is Hai Sun Park, M.D.'s NPI number? ▼
Hai Sun Park, M.D.'s National Provider Identifier (NPI) is 1508805839, issued on 06/05/2006.
Does Hai Sun Park, M.D. prescribe more brand-name or generic drugs? ▼
Hai Sun Park, M.D.'s prescribing is 17% brand-name and 82% generic drugs by claim count, with $2.2M in brand drug costs.
Does Hai Sun Park, M.D. prescribe opioids? ▼
Yes, Hai Sun Park, M.D. had 45 opioid claims in 2023 with an opioid prescribing rate of 1.0%.
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 Hai Sun Park, M.D. prescribe most often? ▼
Based on 2023 Medicare Part D data, Hai Sun Park, M.D.'s most frequently prescribed drugs include Atorvastatin Calcium, Amlodipine Besylate, Losartan Potassium. This reflects Medicare Part D prescriptions only and does not include commercial insurance or other payer types.
Does Hai Sun Park, M.D. accept Medicare? ▼
Hai Sun Park, M.D. appears in CMS Medicare data with 4,333 Part D claims and 316 Medicare beneficiaries in 2023. Contact the provider's office directly to confirm current Medicare enrollment and accepted plans.
How can I verify Hai Sun Park, M.D.'s credentials? ▼
Hai Sun Park, M.D.'s NPI is 1508805839 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 (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.