Physician Profile
Unclaimed ProfileAbout WILLIAMS
John Byron Williams, M.D. practises gastroenterology in Madison, WI. John is a 2000 graduate of Saint Louis University School of Medicine.
Summarised automatically from public NPI registry and CMS Medicare data. Not written or reviewed by this provider. Claim this profile to replace it.
Education & Training
Areas of Expertise
Common questions
What is Dr. Williams's specialty?
Dr. Williams is a gastroenterology in Madison, WI. This is the primary taxonomy recorded against the NPI in the federal registry, listed there as “GASTROENTEROLOGY”.
NPI registry
Where can I find Dr. Williams?
Dr. Williams is listed at 20 S PARK ST SUITE 207, Madison, WI 53715. Addresses come from the NPI registry and can lag a move, so confirm before travelling.
NPI registry
How do I contact Dr. Williams?
The number on file is (608) 287-2680. Guide.md cannot book appointments or pass on messages — please call the office directly.
NPI registry
What is the NPI for Dr. Williams?
Dr. Williams's National Provider Identifier is 1265516421. It is issued by the Centers for Medicare & Medicaid Services and is unique and permanent — it does not change if they move practice.
NPI registry
What is Dr. Williams's medical education?
Dr. Williams attended Saint Louis University School of Medicine, graduating in 2000. This comes from the CMS National Downloadable File.
CMS public data
How much experience does Dr. Williams have?
Dr. Williams has 26 years experience. Calculated from a graduation year of 2000, reported in the CMS National Downloadable File.
CMS public data
What is Dr. Williams known for?
According to Medicare billing data, Dr. Williams performs procedures including biopsy of esophagus, stomach, and/or upper small bowel using a flexible endoscope, biopsy of large bowel using a flexible endoscope and removal of polyps or growths of large bowel using an endoscope with mechanical snare, alongside routine visits and testing. This reflects Medicare patients only and is billing volume, not a measure of quality.
Medicare claims
Is Dr. Williams's profile verified?
Not yet. This profile is built from public federal data and has not been confirmed by Dr. Williams. If this is you, claiming it is free.
Guide.md
Licensing & Certification
Source: NPPES NPI Registry
Contact Information
- (608) 287-2680
- Email not available
Practice Locations
20 S PARK ST SUITE 207
Madison, WI 53715
Procedures Most Often Billed to Medicare
470 services · 437 patients · 15 distinct codes
| Procedure | Type | Code | Services |
|---|---|---|---|
| Biopsy of esophagus, stomach, and/or upper small bowel using a flexible endoscope | Procedure | 43239 |
63 |
| Biopsy of large bowel using a flexible endoscope | Procedure | 45380 |
55 |
| Biopsy of large bowel using a flexible endoscope | Procedure | 45380 |
50 |
| Removal of polyps or growths of large bowel using an endoscope with mechanical snare | Procedure | 45385 |
42 |
| Removal of polyps or growths of large bowel using an endoscope with mechanical snare | Procedure | 45385 |
39 |
| Biopsy of esophagus, stomach, and/or upper small bowel using a flexible endoscope | Procedure | 43239 |
38 |
| Insertion of needle into vein for collection of blood sample | Procedure | 36415 |
26 |
| Diagnostic exam of esophagus, stomach, and/or upper small bowel using a flexible endoscope | Procedure | 43235 |
21 |
| Balloon dilation of esophagus, stomach, and/or upper small bowel using a flexible endoscope, less than 3.0 cm | Procedure | 43249 |
15 |
| Diagnostic exam of large bowel using a flexible endoscope | Procedure | 45378 |
12 |
Source: CMS Medicare public data. Shows how often procedures were billed — not quality of care or patient satisfaction.
Related providers
Connections drawn from the registry and from what providers have told us. A link here is not a referral or an endorsement.
Other gastroenterology specialists at this location 3
Same specialty, same street address — most likely the same department or group.
Related specialists at this location 2
Clinically related specialties at the same address — the people this provider most likely works alongside.
Also at this address 4
Providers at the same street address. Each files their own registry entry, so a shared practice often appears under several different names.
More connections — 31 related providers in 4 groups
Other gastroenterology specialists in Madison 7
Same specialty, same city.
Trained at Saint Louis University School of Medicine 8
Other providers in the same specialty who trained at the same institution.
Class of 2000 at Saint Louis University School of Medicine 8
Providers who graduated from the same medical school in the same year.
Also performs Biopsy of esophagus, stomach, and/or upper small bowel using a flexible endoscope 8
Providers in WI who bill this service to Medicare most often.
Provider data sourced from the NPPES NPI Registry and CMS public datasets. Information is provided for reference and is not medical advice.