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Edit this profileAt a glance
- 20 S Park St, Suite 207, Madison, WI 53715
About Dr. Williams
John B. Williams, M.D. practices gastroenterology in Madison, WI. John is a 2000 graduate of Saint Louis University School of Medicine. Medicare claims data shows John provided 470 services to 437 patients. The services billed most often include biopsy of esophagus, stomach, and/or upper small bowel using a flexible endoscope, biopsy of large bowel using a flexible endoscope, and biopsy of large bowel using a flexible endoscope. The provider's National Provider Identifier (NPI) is 1265516421.
Factual summary compiled by Guide.md from public records; not written by this provider.
Education & Training
Specialty
Credentials & Licensing
Medicare information
Exactly as CMS reports it (National Downloadable File, Opt-Out Affidavits, Order & Referring). Not an insurance directory; confirm coverage with the office.
Contact Information
- (608) 287-2680
- Email not available
Practice Locations
20 S PARK ST SUITE 207
Madison, WI 53715
Conditions Commonly Evaluated or Treated
Within Gastroenterology generally. Availability varies by clinician, training and location — this profile has not been claimed, so nothing here is a personal claim by the provider.
Conditions
Most searched conditions
- Acid reflux
- Celiac disease
- Crohn's disease
- Hemorrhoids
- IBS
- Swallowing difficulties
- Ulcerative colitis
Biliary and pancreas
Colon and anorectal
Esophagus and swallowing
Functional bowel and motility
Liver
- Ascites
- Autoimmune hepatitis
- Cirrhosis
- Fatty liver disease
- Hemochromatosis
- Hepatitis B
- Hepatitis C
- Portal hypertension
Stomach and duodenum
Bowel & Colon
Digestive Symptoms
Gallbladder & Bile Ducts
Procedures & services
Most searched procedures
Lower endoscopy
Upper endoscopy
Capsule and physiology testing
Diagnostic Testing
Liver procedures
Treatments
Procedures Most Often Billed to Medicare
470 services · 437 patients · 15 distinct codes
| Procedure | Type | Code | Services | Compared with peers |
|---|---|---|---|---|
| Biopsy of esophagus, stomach, and/or upper small bowel using a flexible endoscope | Procedure | 43239 |
63 | More often than most peers in Gastroenterology |
| Biopsy of large bowel using a flexible endoscope | Procedure | 45380 |
55 | More often than most peers in Gastroenterology |
| Biopsy of large bowel using a flexible endoscope | Procedure | 45380 |
50 | More often than most peers in Gastroenterology |
| Removal of polyps or growths of large bowel using an endoscope with mechanical snare | Procedure | 45385 |
42 | More often than most peers in Gastroenterology |
| Removal of polyps or growths of large bowel using an endoscope with mechanical snare | Procedure | 45385 |
39 | More often than most peers in Gastroenterology |
| Biopsy of esophagus, stomach, and/or upper small bowel using a flexible endoscope | Procedure | 43239 |
38 | More often than most peers in Gastroenterology |
| Insertion of needle into vein for collection of blood sample | Procedure | 36415 |
26 | As often as other peers in Gastroenterology |
| Diagnostic exam of esophagus, stomach, and/or upper small bowel using a flexible endoscope | Procedure | 43235 |
21 | As often as other peers in Gastroenterology |
| Balloon dilation of esophagus, stomach, and/or upper small bowel using a flexible endoscope, less than 3.0 cm | Procedure | 43249 |
15 | Less often than most peers in Gastroenterology |
| Diagnostic exam of large bowel using a flexible endoscope | Procedure | 45378 |
12 | Less often than most peers in Gastroenterology |
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 gastroenterologists at this location 2
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 — 32 related providers in 4 groups
Other gastroenterologists in Madison 8
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.
Common questions
What is John B. Williams's specialty?
John B. Williams is a gastroenterologist in Madison, WI. That is the designation recorded for this NPI in the federal registry, where it is listed as “Gastroenterology”.
NPI registry
Where can I find John B. Williams?
John B. 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 John B. Williams?
The number on file is (608) 287-2680. Contact the office directly to confirm availability and scheduling.
NPI registry
What is the NPI for John B. Williams?
John B. 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 John B. Williams's education?
John B. 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 John B. Williams have?
John B. Williams has 26 years experience. Calculated from a graduation year of 2000, reported in the CMS National Downloadable File.
CMS public data
What is John B. Williams known for?
According to Medicare billing data, John B. 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 John B. Williams's profile verified?
Not yet. This profile is built from public federal data and has not been confirmed by John B. Williams. If this is you, claiming it is free.
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