NPI registry status
Active
2026 NPPES data Emergency Medicine Physician NPI 1871673830 MD
Verify on CMS → John Chafos, MD
Emergency Medicine Physician in Green Brook, 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 64,463 in Emergency 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 · 560 beneficiaries · Emergency Medicine Physician avg: 352
Generic prescribing
88%
generic claims · 11% brand-name · higher generic rates reduce patient out-of-pocket costs
Source: CMS Medicare Part D Prescriber Public Use File, 2023
What the federal data shows
John Chafos, MD filed 4,313 Medicare Part D claims in 2023 as an Emergency Medicine Physician in Green Brook, New Jersey, prescribing 88% generic.
- 4K
- Part D claims, 2023
- 88%
- generic prescribing
- 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.
John Chafos, MD's Medicare Part D volume vs every U.S. prescriber
Total Medicare Part D claims, 2023, across all CMS prescribers nationally
4,313 Top 8% higher than 92% of 1,370,886 prescribers
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.
Source CMS Medicare Part D Prescriber Public Use File · 2023
✓
Board certification likely (heuristic, not verified)
John Chafos, MD practices in an ABMS-board-eligible specialty and shows active CMS Medicare participation + 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 John Chafos, MD?
Quality data not reportedPrimary specialty
Emergency Medicine Physician
Medicare Part D claims
4,313 12× vs specialty avg
Specialty distribution in New Jersey
How Emergency 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 Emergency 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).
John Chafos, MD appears in the CMS NPPES registry as an Emergency Medicine Physician provider holding MD credentials at 257 RT 22 EAST, Green Brook, NJ, 08812, with a listed phone of (732) 968-8832. NPI 1871673830 was issued on 10/16/2006.
Medicare Part D records for calendar year 2023 show 4,313 prescription claims written by this provider, covering 560 Medicare beneficiaries and totaling roughly $457K in drug spend, split 11% brand-name and 88% generic by claim count, with an opioid prescribing rate of 1.0%.
Emergency Medicine Physician is a high-volume specialty nationwide, with 64,463 enrolled providers across 56 states and an average of 352 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 | 1871673830 |
|---|---|
| Specialty | Emergency Medicine Physician |
| Credentials | MD |
| Gender | Male |
| NPI Issued | 10/16/2006 |
Hospital and facility affiliations
Facilities where John Chafos, MD 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.
Family Care PA
Hillsborough, NJ
Affiliations sourced from CMS Doctors and Clinicians National Downloadable File; hospital ratings from CMS Hospital General Information dataset (cross-referenced by facility name + state).
Brand vs generic prescribing mix · Typical
John Chafos, MD - brand share 11.0%
Emergency Medicine Physician average
11% brand-name claims vs 88% generic, on 4,313 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.
4,313
Total Claims
$457K
Total Drug Cost
560
Medicare Beneficiaries
Prescribing Breakdown
- 30-Day Fills
- 8,851
- Total Day Supply
- 238,704
- Brand vs Generic
- 11% brand / 88% generic
- Brand Drug Cost
- $368K
- Generic Drug Cost
- $87K
- Opioid Claims
- 45 (1.0% rate)
- Antibiotic Claims
- 567
Patient Demographics
- Average Patient Age
- 74.2 years
- Avg HCC Risk Score
- 1.11
- Gender Split
- 58% female / 42% male
- Age Distribution
- <65: 28, 65-74: 275, 75-84: 195, 85+: 62
Top Prescribed Drugs (Medicare Part D)
Top drugs by claim count for calendar year 2023. Based on Medicare Part D data only.
What John Chafos, MD prescribes most
Top Medicare Part D drugs by claim count, 2023
- Dexamethasone
Dexamethasone
215 claims
- Prednisone
Prednisone
150 claims
- Atorvastatin Calcium
Atorvastatin Calcium
136 claims
- Rosuvastatin Calcium
Rosuvastatin Calcium
125 claims
- Metformin Hcl
Metformin Hcl
119 claims
- Metoprolol Succinate
Metoprolol Succinate
119 claims
- Amlodipine Besylate
Amlodipine Besylate
111 claims
- Cefdinir
Cefdinir
108 claims
| Drug | Claims |
|---|---|
| Dexamethasone | 215 |
| Prednisone | 150 |
| Atorvastatin Calcium | 136 |
| Rosuvastatin Calcium | 125 |
| Metformin Hcl | 119 |
| Metoprolol Succinate | 119 |
| Amlodipine Besylate | 111 |
| Cefdinir | 108 |
| Azithromycin | 107 |
| Amoxicillin-Clavulanate Potass Amoxicillin/Potassium Clav | 84 |
* Counts below 11 are suppressed by CMS for patient privacy. Generic names shown where available from CMS Part D data.
Emergency Medicine Physician Overview
How John Chafos, MD fits within the Emergency Medicine Physician landscape nationally.
64,463
Emergency Medicine Physician Providers in US
56
States with Emergency Medicine Physician
352
Avg Claims per Provider
John Chafos, MD's 4,313 claims are above the specialty average of 352.
Nearby Emergency 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 Chafos.
Dr. Tareef Abbasi
MD
Clifton, NJ
Dr. Mohammad Abboud
MD
Hackensack, NJ
Dr. Moheb Abdelmalek
MD
Perth Amboy, NJ
Dr. Ibrahim Abdullah
M.D.
Willingboro, NJ
Dr. Kate Aberger
MD
Paterson, NJ
Compare Emergency 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 Emergency 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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Frequently Asked Questions
What is John Chafos, MD's specialty? ▼
John Chafos, MD specializes in Emergency Medicine Physician and practices in Green Brook, New Jersey. Credentials: MD.
How much does John Chafos, MD prescribe under Medicare Part D? ▼
In 2023, John Chafos, MD wrote 4,313 Medicare Part D claims totaling $457K in drug costs for 560 beneficiaries.
Where is John Chafos, MD located? ▼
John Chafos, MD is located at 257 RT 22 EAST, Green Brook, NJ, 08812. Phone: (732) 968-8832.
What is John Chafos, MD's NPI number? ▼
John Chafos, MD's National Provider Identifier (NPI) is 1871673830, issued on 10/16/2006.
Does John Chafos, MD prescribe more brand-name or generic drugs? ▼
John Chafos, MD's prescribing is 11% brand-name and 88% generic drugs by claim count, with $368K in brand drug costs.
Does John Chafos, MD prescribe opioids? ▼
Yes, John Chafos, MD had 45 opioid claims in 2023 with an opioid prescribing rate of 1.0%.
How many Emergency Medicine Physician providers are there in the US? ▼
There are 64,463 Emergency Medicine Physician providers across 56 states in the US. The average Emergency Medicine Physician provider writes 352 Medicare Part D claims per year.
What drugs does John Chafos, MD prescribe most often? ▼
Based on 2023 Medicare Part D data, John Chafos, MD's most frequently prescribed drugs include Dexamethasone, Prednisone, Atorvastatin Calcium. This reflects Medicare Part D prescriptions only and does not include commercial insurance or other payer types.
Does John Chafos, MD accept Medicare? ▼
John Chafos, MD appears in CMS Medicare data with 4,313 Part D claims and 560 Medicare beneficiaries in 2023. Contact the provider's office directly to confirm current Medicare enrollment and accepted plans.
How can I verify John Chafos, MD's credentials? ▼
John Chafos, MD's NPI is 1871673830 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.