Doctor profile · Federal record

Dr. John Chafos, MD

Internal Medicine Physician (CMS: Family Practice) · Emergency Medicine Physician · Green Brook, NJ

  • NPI 1871673830
  • Accepts Medicare
  • 38 yrs in practice
  • Male
  • Group practice
  • No sanctions

Practice & contact

NPPES Updated May 11, 2026
Primary practice
257 Rt 22 East
Green Brook, NJ 08812
(732) 968-8832
fax (732) 968-2187

Credentials & registration

NPPES · NUCC
NPI registered
October 2006 — 20 yrs on file
Profile last updated
March 29, 2011
Year of graduation
1988 — 38 yrs since
Specialty taxonomy
207R00000X — NUCC code
State license (1)
New Jersey #25MA05399400

Federal sanctions & exclusions

OIG LEIE Updated May 11, 2026

No sanctions, exclusions or revocations on file

Checked against OIG LEIE on NPI 1871673830. Last verified May 11, 2026.

Medicare procedures · 2023

Top services delivered

CMS Provider Utilization
Total services
5,263
Distinct HCPCS
10
Medicare allowed
$201,245
HCPCS Description Services Patients Avg allowed
99213 Established patient office or other outpatient visit, 20-29 minutes 667 310 $97
99214 Established patient office or other outpatient visit, 30-39 minutes 617 283 $136
J1100 Injection, dexamethasone sodium phosphate, 1 mg 592 106 $0
36415 Insertion of needle into vein for collection of blood sample 410 226 $3
J0696 Injection, ceftriaxone sodium, per 250 mg 381 71 $0
96372 Injection of drug or substance under skin or into muscle 367 166 $15
85025 Complete blood cell count (red cells, white blood cell, platelets), automated test and automated differential white blood cell count 358 209 $8
81003 Automated urinalysis test 316 196 $2
83036 Hemoglobin a1c level 214 143 $10
87428 Detection test by immunoassay technique for severe acute respiratory syndrome coronavirus and influenza 198 161 $31

In context: peer comparison

Among 2 peers in this city , average services per provider: 121. This provider delivers 43× the peer median.

Medicare Part D · 2023

Top prescriptions

CMS Part D Prescriber
Total claims
1,621
Patients
931
Total drug cost
$20,682
Drug Type Claims Patients Total cost
Dexamethasone Generic 215 163 $750
Prednisone Generic 150 77 $807
Atorvastatin Calcium Generic 136 58 $1,660
Rosuvastatin Calcium Generic 125 53 $3,268
Metformin Hcl Generic 119 48 $1,201
Metoprolol Succinate Generic 119 47 $2,591
Amlodipine Besylate Generic 111 50 $898
Cefdinir Generic 108 85 $2,736
Azithromycin Generic 107 89 $586
Amoxicillin-Clavulanate Potass (Amoxicillin/Potassium Clav) Brand 84 70 $937

Frequently asked questions

Auto-generated from federal data
What is Dr. John Chafos's medical specialty?
Dr. John Chafos practices Internal Medicine Physician in Green Brook, NJ.
Where does Dr. John Chafos practice?
Dr. John Chafos practices at 257 Rt 22 East, Green Brook, NJ 08812. Office phone: 7329688832.
What is Dr. John Chafos's NPI?
Dr. John Chafos's National Provider Identifier (NPI) is 1871673830, issued by NPPES.
Does Dr. John Chafos accept Medicare assignment?
Yes. Dr. John Chafos accepts Medicare assignment, meaning Medicare-allowed amounts are accepted as full payment for covered services.
What procedures does Dr. John Chafos commonly perform?
Top Medicare-reported procedures in 2023: Established patient office or other outpatient visit (HCPCS 99213); Established patient office or other outpatient visit (HCPCS 99214); Injection, dexamethasone sodium phosphate, 1 mg (HCPCS J1100). Source: CMS Medicare Physician & Other Practitioners file.