Jason Williams, MD
NPI 1083894257 · Gastroenterology Physician · San Jose, CA
Enrolled with Medicare as Practitioner - Gastroenterology · source: CMS PECOS Public Provider Enrollment (2026.04.01)
Jason Williams, MD is a Gastroenterology Physician provider in San Jose, CA (NPI 1083894257).
Provider details
- NPI number
- 1083894257
- Entity type
- Individual
- Primary specialty
- Gastroenterology PhysicianAllopathic & Osteopathic Physicians
- Credential
- MD
- Sex
- Male
- Sole proprietor
- No
- License
- A96986 (CA)
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
18 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
184 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) |
|---|---|---|
| Moderate Sedation Services Provided By the Same Physician Or Other Qualified Health Care Professional Performing a Gastrointestinal Endoscopic Service That Sedation Supports, Requiring the Presence of an Independent Trained Observer to Assist in the MonitoG0500 | 47 | $6 |
| Established Patient Office Or Other Outpatient Visit With Moderate Level of Decision Making, If Using Time, 30 Minutes Or More99214 | 42 | $111 |
| Initial Hospital Care With Straightforward Or Low-Level Medical Decision Making, If Using Time, at Least 55 Minutes99222 | 30 | $146 |
| Biopsy of Large Bowel Using a Flexible Endoscope45380 | 25 | $93 |
| Removal of Polyps Or Growths of Large Bowel Using an Endoscope With Mechanical Snare45385 | 25 | $285 |
What this provider prescribes (Medicare Part D)
Top drugs by Medicare Part D claim volume, 2024 · 7 distinct drugs on file.
| Drug | Part D claims (2024) | Beneficiaries |
|---|---|---|
| Rifaximinbrand: Xifaxan | 36 | — |
| Omeprazole | 36 | 16 |
| Tenofovir Disoproxil Fumarate | 23 | — |
| Entecavir | 21 | — |
| Tenofovir Alafenamidebrand: Vemlidy | 12 | — |
| Linaclotidebrand: Linzess | 12 | — |
| Spironolactone | 11 | — |
Practice location
Mailing address
Registry dates
- Enumerated
- 2007-11-06
- Last updated
- 2012-07-03
Frequently asked questions
- What is Jason Williams's NPI number?
- Jason Williams's National Provider Identifier (NPI) is 1083894257, a unique 10-digit ID issued by CMS for use in standard healthcare transactions.
- What is Jason Williams's specialty?
- Jason Williams is listed in the NPPES registry with a primary specialty of Gastroenterology Physician (Allopathic & Osteopathic Physicians).
- Where is Jason Williams located?
- Jason Williams's practice location on file with NPPES is 751 S Bascom Ave, San Jose, CA 95128-2604.
- What is Jason Williams's phone number?
- The practice phone number listed in the NPPES registry for Jason Williams is (408) 885-7947.
- Does Jason Williams accept Medicare?
- Jason Williams is approved to bill Medicare according to CMS PECOS enrollment data (2026.04.01). Confirm current participation with the provider before scheduling.
- Is Jason Williams's NPI active?
- Yes — Jason Williams's NPI (1083894257) is active in the NPPES registry as of the last update on 2012-07-03.
Source: CMS NPPES Data Dissemination (June 2026). NPI Central is not affiliated with CMS. Data is provided as-is from the public registry.