William Vanneman, M.D.
NPI 1124075718 · Gastroenterology Physician · Winchester, MA
Enrolled with Medicare as Practitioner - Gastroenterology · source: CMS PECOS Public Provider Enrollment (2026.04.01)
William Vanneman, M.D. is a Gastroenterology Physician provider in Winchester, MA (NPI 1124075718).
Provider details
- NPI number
- 1124075718
- Entity type
- Individual
- Primary specialty
- Gastroenterology PhysicianAllopathic & Osteopathic Physicians
- Credential
- M.D.
- Sex
- Male
- Sole proprietor
- No
- License
- 38046 (MA)
Specialties & taxonomies
Allopathic & Osteopathic Physicians
Profile Score
A profile completeness & documented-activity index — NOT a quality, outcomes, or patient-satisfaction rating.
- Registry tenure28% of score
20 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
200 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) |
|---|---|---|
| Initial Hospital Care With Straightforward Or Low-Level Medical Decision Making, If Using Time, at Least 55 Minutes99222 | 49 | $132 |
| Subsequent Hospital Care With Moderate Levelof Medical Decision Making, If Using Time, at Least 35 Minutes99232 | 32 | $80 |
| Diagnostic Exam of Esophagus, Stomach, And/Or Upper Small Bowel Using a Flexible Endoscope43235 | 31 | $114 |
| Biopsy of Esophagus, Stomach, And/Or Upper Small Bowel Using a Flexible Endoscope43239 | 17 | $105 |
| Biopsy of Large Bowel Using a Flexible Endoscope45380 | 16 | $97 |
| Subsequent Hospital Care With Straightforward Or Low Level of Medical Decision Making, Per Day, If Using Time, at Least 25 Minutes |
Practice location
Mailing address
Registry dates
- Enumerated
- 2006-05-28
- Last updated
- 2012-11-06
Frequently asked questions
- What is William Vanneman's NPI number?
- William Vanneman's National Provider Identifier (NPI) is 1124075718, a unique 10-digit ID issued by CMS for use in standard healthcare transactions.
- What is William Vanneman's specialty?
- William Vanneman is listed in the NPPES registry with a primary specialty of Gastroenterology Physician (Allopathic & Osteopathic Physicians).
- Where is William Vanneman located?
- William Vanneman's practice location on file with NPPES is 955 Main St, Winchester, MA 01890-1961.
- What is William Vanneman's phone number?
- The practice phone number listed in the NPPES registry for William Vanneman is (781) 729-5855.
- Does William Vanneman accept Medicare?
- William Vanneman is approved to bill Medicare according to CMS PECOS enrollment data (2026.04.01). Confirm current participation with the provider before scheduling.
- Is William Vanneman's NPI active?
- Yes — William Vanneman's NPI (1124075718) is active in the NPPES registry as of the last update on 2012-11-06.
Source: CMS NPPES Data Dissemination (June 2026). NPI Central is not affiliated with CMS. Data is provided as-is from the public registry.