Thomas Chen, MD
NPI 1891870317 · Medical Oncology Physician · San Jose, CA
Enrolled with Medicare as Practitioner - Medical Oncology · source: CMS PECOS Public Provider Enrollment (2026.04.01)
Thomas Chen, MD is a Medical Oncology Physician provider in San Jose, CA (NPI 1891870317).
Provider details
- NPI number
- 1891870317
- Entity type
- Individual
- Primary specialty
- Medical Oncology PhysicianAllopathic & Osteopathic Physicians
- Credential
- MD
- Sex
- Male
- Sole proprietor
- No
- License
- G84369 (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 tenure25% of score
19 yrs in NPPES registry
- Profile completeness25% of score
100% of core fields populated
- Practice footprint15% of score
1 documented practice location
- Medicare service volume (vs. specialty peers)25% of score
3,182 Medicare services, 2024 (ranked within specialty)
- Open Payments transparency10% of score
Has Open Payments disclosures (2024)
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 .
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) |
|---|---|---|
| Visit Complexity Inherent to Evaluation and Management Associated With Medical Care Services That Serve As the Continuing Focal Point for All Needed Health Care Services And/Or With Medical Care Services That Are Part of Ongoing Care Related to a Patient'SG2211 | 1,272 | $19 |
| Established Patient Office Or Other Outpatient Visit With High Level of Medical Decision Making, If Using Time, 40 Minutes Or More99215 | 797 | $168 |
| Established Patient Office Or Other Outpatient Visit With Moderate Level of Decision Making, If Using Time, 30 Minutes Or More99214 | 677 | $116 |
| Subsequent Hospital Care With Moderate Levelof Medical Decision Making, If Using Time, at Least 50 Minutes99233 | 222 | $133 |
| New Patient Office Or Other Outpatient Visit With a High Level of Medical Decision Making, If Using Time, 60 Minutes Or More99205 | 87 | $206 |
What this provider prescribes (Medicare Part D)
Top drugs by Medicare Part D claim volume, 2024 · 21 distinct drugs on file.
| Drug | Part D claims (2024) | Beneficiaries |
|---|---|---|
| Hydroxyurea | 77 | 23 |
| Prednisone | 56 | 24 |
| Dexamethasone | 47 | 23 |
| Apixabanbrand: Eliquis | 47 | 19 |
| Ondansetron Hcl | 45 | 21 |
| Prochlorperazine Maleate | 40 | 24 |
| Anastrozole | 38 | 18 |
| Imatinib Mesylate |
Transparency — industry payments
Based on CMS Open Payments, 2024; not all care is captured.
$129 across 1 record (Open Payments 2024)
Open Payments discloses payments and transfers of value (meals, travel, consulting, research, royalties) from drug and device makers to providers. This is a transparency signal, not a verdict — such payments are legal and common, and their presence is neither an endorsement nor a criticism. Source: CMS Open Payments, program year 2024.
Practice location
Mailing address
Registry dates
- Enumerated
- 2006-10-25
- Last updated
- 2024-04-17
- Certified
- 2024-04-17
Frequently asked questions
- What is Thomas Chen's NPI number?
- Thomas Chen's National Provider Identifier (NPI) is 1891870317, a unique 10-digit ID issued by CMS for use in standard healthcare transactions.
- What is Thomas Chen's specialty?
- Thomas Chen is listed in the NPPES registry with a primary specialty of Medical Oncology Physician (Allopathic & Osteopathic Physicians).
- Where is Thomas Chen located?
- Thomas Chen's practice location on file with NPPES is 2589 Samaritan Dr Ste 200, San Jose, CA 95124-4102.
- What is Thomas Chen's phone number?
- The practice phone number listed in the NPPES registry for Thomas Chen is (408) 426-4900.
- Does Thomas Chen accept Medicare?
- Thomas Chen is approved to bill Medicare according to CMS PECOS enrollment data (2026.04.01). Confirm current participation with the provider before scheduling.
- Is Thomas Chen's NPI active?
- Yes — Thomas Chen's NPI (1891870317) is active in the NPPES registry as of the last update on 2024-04-17.
Source: CMS NPPES Data Dissemination (June 2026). NPI Central is not affiliated with CMS. Data is provided as-is from the public registry.