John Chafos, MD
NPI 1871673830 · Internal Medicine Physician · Green Brook, NJ
Enrolled with Medicare as Practitioner - Family Practice · source: CMS PECOS Public Provider Enrollment (2026.04.01)
John Chafos, MD is a Internal Medicine Physician provider in Green Brook, NJ (NPI 1871673830).
Provider details
- NPI number
- 1871673830
- Entity type
- Individual
- Primary specialty
- Internal Medicine PhysicianAllopathic & Osteopathic Physicians
- Credential
- MD
- Sex
- Male
- Sole proprietor
- No
- License
- 25MA05399400 (NJ)
Specialties & taxonomies
Allopathic & Osteopathic Physicians
Allopathic & Osteopathic Physicians
Profile Score
A profile completeness & documented-activity index — NOT a quality, outcomes, or patient-satisfaction rating.
- Registry tenure28% of score
19 yrs in NPPES registry
- Profile completeness28% of score
100% of core fields populated
- Practice footprint17% of score
1 documented practice location
- Medicare service volume (vs. specialty peers)28% of score
2,789 Medicare services, 2024 (ranked within specialty)
Medicare volume is ranked against active providers in the same specialty. Signals a provider has no public data for (e.g. Medicare claims) are left out of the score entirely — never counted as zero — so providers without that data are not penalized. See the full formula and weights in our methodology.
What this provider does (Medicare)
Based on Medicare fee-for-service claims, 2024; not all care is captured.
| Service (HCPCS) | Medicare services | Typical Medicare-allowed (2024) |
|---|---|---|
| Established Patient Office Or Other Outpatient Visit With Low Level OD Decision Making, If Using Time, 20 Minutes Or More99213 | 589 | $98 |
| Established Patient Office Or Other Outpatient Visit With Moderate Level of Decision Making, If Using Time, 30 Minutes Or More99214 | 512 | $140 |
| Injection of Drug Or Substance Under Skin Or Into Muscle96372 | 348 | $16 |
| Insertion of Needle Into Vein for Collection of Blood Sample36415 | 263 | $6 |
| Automated Urinalysis Test81003 | 217 | $2 |
| Complete Blood Cell Count (red Cells, White Blood Cell, Platelets), Automated Test and Automated Differential White Blood Cell Count85025 | 213 |
What this provider prescribes (Medicare Part D)
Top drugs by Medicare Part D claim volume, 2024 · 103 distinct drugs on file.
| Drug | Part D claims (2024) | Beneficiaries |
|---|---|---|
| Dexamethasone | 277 | 227 |
| Atorvastatin Calcium | 166 | 64 |
| Rosuvastatin Calcium | 152 | 61 |
| Metoprolol Succinate | 126 | 49 |
| Cefdinir | 125 | 108 |
| Amlodipine Besylate | 124 | 57 |
| Metformin Hcl | 120 |
Practice location
Mailing address
Registry dates
- Enumerated
- 2006-10-16
- Last updated
- 2011-03-29
Frequently asked questions
- What is John Chafos's NPI number?
- John Chafos's National Provider Identifier (NPI) is 1871673830, a unique 10-digit ID issued by CMS for use in standard healthcare transactions.
- What is John Chafos's specialty?
- John Chafos is listed in the NPPES registry with a primary specialty of Internal Medicine Physician (Allopathic & Osteopathic Physicians).
- Where is John Chafos located?
- John Chafos's practice location on file with NPPES is 257 Rt 22 East, Green Brook, NJ 08812.
- What is John Chafos's phone number?
- The practice phone number listed in the NPPES registry for John Chafos is (732) 968-8832.
- Does John Chafos accept Medicare?
- John Chafos is approved to bill Medicare according to CMS PECOS enrollment data (2026.04.01). Confirm current participation with the provider before scheduling.
- Is John Chafos's NPI active?
- Yes — John Chafos's NPI (1871673830) is active in the NPPES registry as of the last update on 2011-03-29.
Source: CMS NPPES Data Dissemination (June 2026). NPI Central is not affiliated with CMS. Data is provided as-is from the public registry.