Geoffrey Spencer, MD
NPI 1578625828 · Gastroenterology Physician · San Jose, CA
Enrolled with Medicare as Practitioner - Gastroenterology · source: CMS PECOS Public Provider Enrollment (2026.04.01)
Geoffrey Spencer, MD is a Gastroenterology Physician provider in San Jose, CA (NPI 1578625828).
Provider details
- NPI number
- 1578625828
- Entity type
- Individual
- Primary specialty
- Gastroenterology PhysicianAllopathic & Osteopathic Physicians
- Credential
- MD
- Sex
- Male
- Sole proprietor
- Yes
- License
- A108150 (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
19 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
1,604 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) |
|---|---|---|
| Biopsy of Large Bowel Using a Flexible Endoscope45380 | 451 | $112 |
| Removal of Polyps Or Growths of Large Bowel Using an Endoscope With Mechanical Snare45385 | 286 | $284 |
| Established Patient Office Or Other Outpatient Visit With Moderate Level of Decision Making, If Using Time, 30 Minutes Or More99214 | 274 | $154 |
| Biopsy of Esophagus, Stomach, And/Or Upper Small Bowel Using a Flexible Endoscope43239 | 239 | $92 |
| Initial Hospital Care With Moderate Level of Medical Decision Making, If Using Time, at Least 75 Minutes99223 | 91 | $195 |
| Established Patient Office Or Other Outpatient Visit With Low Level OD Decision Making, If Using Time, 20 Minutes Or More |
What this provider prescribes (Medicare Part D)
Top drugs by Medicare Part D claim volume, 2024 · 17 distinct drugs on file.
| Drug | Part D claims (2024) | Beneficiaries |
|---|---|---|
| Sodium, Potassium,mag Sulfatesbrand: Sod Sulf-Potass Sulf-Mag Sulf | 247 | 247 |
| Omeprazole | 182 | 62 |
| Sodium Chloride/Nahco3/Kcl/Pegbrand: Peg 3350-Electrolyte | 172 | 169 |
| Pantoprazole Sodium | 120 | 42 |
| Famotidine | 63 | 22 |
| Mesalamine | 40 | 11 |
| Dexlansoprazolebrand: Dexlansoprazole Dr |
Practice location
Mailing address
Registry dates
- Enumerated
- 2006-12-14
- Last updated
- 2009-07-14
Frequently asked questions
- What is Geoffrey Spencer's NPI number?
- Geoffrey Spencer's National Provider Identifier (NPI) is 1578625828, a unique 10-digit ID issued by CMS for use in standard healthcare transactions.
- What is Geoffrey Spencer's specialty?
- Geoffrey Spencer is listed in the NPPES registry with a primary specialty of Gastroenterology Physician (Allopathic & Osteopathic Physicians).
- Where is Geoffrey Spencer located?
- Geoffrey Spencer's practice location on file with NPPES is 2440 Samaritan Dr, San Jose, CA 95124-3911.
- What is Geoffrey Spencer's phone number?
- The practice phone number listed in the NPPES registry for Geoffrey Spencer is (408) 626-7375.
- Does Geoffrey Spencer accept Medicare?
- Geoffrey Spencer is approved to bill Medicare according to CMS PECOS enrollment data (2026.04.01). Confirm current participation with the provider before scheduling.
- Is Geoffrey Spencer's NPI active?
- Yes — Geoffrey Spencer's NPI (1578625828) is active in the NPPES registry as of the last update on 2009-07-14.
Source: CMS NPPES Data Dissemination (June 2026). NPI Central is not affiliated with CMS. Data is provided as-is from the public registry.