Quick answers
- Does Geoffrey S. Spencer accept Medicare assignment?
- Yes. Medicare's clinician data says Geoffrey S. Spencer accepts Medicare assignment (the Medicare-approved amount as full payment for covered services), as of October 2, 2026. Ask the office to confirm before your visit.
- How many Medicare patients does Geoffrey S. Spencer see?
- In 2024, CMS data shows 874 Original Medicare patients and 1,696 services for Geoffrey S. Spencer. This counts Original Medicare only and measures volume, not quality.
- What is Geoffrey S. Spencer's NPI number?
- 1578625828. The NPI (National Provider Identifier) is the clinician's permanent federal ID; you can look it up in the official NPI Registry.
Medicare activity in 2024
Official CMS public-use data for Geoffrey S. Spencer, data year 2024 (released May 21, 2026). It covers Original Medicare (fee-for-service) patients only, not Medicare Advantage or other insurance. It shows volume, not quality or outcomes. CMS hides any count of 10 or fewer patients.
| Original Medicare patients | 874 |
|---|---|
| Services billed to Medicare | 1,696 |
| Different services or procedures | 34 |
| Participating Medicare provider | Yes |
| Average age of these patients | 75 |
Most frequent services
- Biopsy of large bowel using a flexible endoscope (45380)451 services
- Removal of polyps or growths of large bowel using an endoscope with mechanical snare (45385)286 services
- Established patient office or other outpatient visit with moderate level of decision making, if using time, 30 minutes or more (99214)274 services
- Biopsy of esophagus, stomach, and/or upper small bowel using a flexible endoscope (43239)239 services
- Initial hospital care with moderate level of medical decision making, if using time, at least 75 minutes (99223)91 services
Chronic conditions among these patients
Share of this clinician’s Original Medicare patients with each condition, as published by CMS (it describes the patients, not the care given).
- High cholesterol75%
- High blood pressure70%
- Arthritis41%
- Ischemic heart disease30%
- Diabetes24%
- Osteoporosis23%
Hospitals where Geoffrey S. Spencer works
Medicare's Facility Affiliation Data lists Geoffrey S. Spencer at these hospitals (updated October 2, 2026). Each hospital page shows its address, phone, emergency services, Medicare rating and all its clinicians. Star rating and emergency services: Hospital General Information (CMS), data updated October 26, 2026.
- El Camino HealthMountain View, CA · Acute Care Hospital · Medicare rating: 4 of 5 stars · Emergency services: listed by Medicare · CCN 050308
- Good Samaritan HospitalSan Jose, CA · Acute Care Hospital · Medicare rating: 2 of 5 stars · Emergency services: listed by Medicare · CCN 050380
- Stanford Health CareStanford, CA · Acute Care Hospital · Medicare rating: 5 of 5 stars · Emergency services: listed by Medicare · CCN 050441
Practice locations
Addresses where Geoffrey S. Spencer is enrolled with Medicare (CMS data updated October 2, 2026).
- 2425 Samaritan DrSan Jose, CA 95124 (408) 559‑2011
- 2506 Samaritan CtSan Jose, CA 95124 (408) 739‑6000
- 370 Distel CirLos Altos, CA 94022 (650) 254‑5200
- 795 El Camino RealPalo Alto, CA 94301 (415) 600‑1020
- 815 Pollard RdLos Gatos, CA 95032 (408) 378‑6131
Group practices
Medicare enrollment lists Geoffrey S. Spencer as a member of this group (CMS data updated October 2, 2026).
- Sutter Bay Medical Foundation3,829 clinicians in the group
Specialties
- Gastroenterologyprimary
Other gastroenterologists in San Jose
Clinicians with the same Medicare primary specialty in San Jose, CA — not a recommendation.
Other clinicians in Sutter Bay Medical Foundation
Medicare enrollment lists these clinicians in the same group practice — not a recommendation.
Clinician information
| Credential | MD |
|---|---|
| Medical school | Eastern Virginia Medical School |
| Graduation year | 2000 (26 years since medical school) |
| Gender (as listed) | Male |
| Medicare assignment | Accepts (Medicare-approved amount as full payment) |
| Telehealth | Offers telehealth services |
| NPI (National Provider Identifier) | 1578625828 |
| Corrections | Report an error or suggest an update → |
Most corrections must be made at the source: clinicians update their NPI Registry record (NPPES) and their Medicare enrollment (PECOS); this page follows the next data release.
Sources
- Facility Affiliation Data — Centers for Medicare & Medicaid Services (CMS), data updated October 2, 2026, retrieved October 29, 2026
- Hospital General Information — CMS, data updated October 26, 2026, retrieved November 13, 2026
- National Downloadable File (Doctors and Clinicians) — CMS, data updated October 2, 2026, retrieved October 29, 2026
- Medicare Physician & Other Practitioners - by Provider — CMS, data year 2024, released May 21, 2026; Medicare Physician & Other Practitioners - by Provider and Service
- NPI Registry — U.S. Department of Health and Human Services (NPPES), the clinician’s official record
- Medicare Care Compare — official Medicare tool to look up clinicians