Yiann Chen, MD
NPI 1891912689 · Nephrology Physician · Oakland, CA
Enrolled with Medicare as Practitioner - Nephrology · source: CMS PECOS Public Provider Enrollment (2026.04.01)
Yiann Chen, MD is a Nephrology Physician provider in Oakland, CA (NPI 1891912689).
Provider details
- NPI number
- 1891912689
- Entity type
- Individual
- Primary specialty
- Nephrology PhysicianAllopathic & Osteopathic Physicians
- Credential
- MD
- Sex
- Male
- Sole proprietor
- No
- License
- A100448 (CA)
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
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
70 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) |
|---|---|---|
| Subsequent Hospital Care With Moderate Levelof Medical Decision Making, If Using Time, at Least 35 Minutes99232 | 57 | $88 |
| Initial Hospital Care With Straightforward Or Low-Level Medical Decision Making, If Using Time, at Least 55 Minutes99222 | 13 | $145 |
Typical Medicare-allowed amounts for these services range $88–$145 (2024). The Medicare-allowed amount is what Medicare recognizes for a service under fee-for-service — a reference figure for 2024, not a price quote and not what you would be billed. Medicare Part B covers roughly an eighth of all NPIs (65+ skew); services with fewer than 11 beneficiaries are suppressed by CMS. Source: CMS Medicare Physician & Other Practitioners, by Provider & Service.
What this provider prescribes (Medicare Part D)
Top drugs by Medicare Part D claim volume, 2024 · 13 distinct drugs on file.
| Drug | Part D claims (2024) | Beneficiaries |
|---|---|---|
| Losartan Potassium | 71 | 34 |
| Amlodipine Besylate | 65 | 33 |
| Sevelamer Carbonate | 52 | 27 |
| Calcium Acetate | 43 | 21 |
| Furosemide | 28 | 16 |
| Empagliflozinbrand: Jardiance | 26 | — |
| Gentamicin Sulfate | 22 | — |
Practice location
Mailing address
Registry dates
- Enumerated
- 2007-04-20
- Last updated
- 2021-12-09
Frequently asked questions
- What is Yiann Chen's NPI number?
- Yiann Chen's National Provider Identifier (NPI) is 1891912689, a unique 10-digit ID issued by CMS for use in standard healthcare transactions.
- What is Yiann Chen's specialty?
- Yiann Chen is listed in the NPPES registry with a primary specialty of Nephrology Physician (Allopathic & Osteopathic Physicians).
- Where is Yiann Chen located?
- Yiann Chen's practice location on file with NPPES is 275 W Macarthur Blvd, Oakland, CA 94611-5641.
- What is Yiann Chen's phone number?
- The practice phone number listed in the NPPES registry for Yiann Chen is (510) 752-1000.
- Does Yiann Chen accept Medicare?
- Yiann Chen is approved to bill Medicare according to CMS PECOS enrollment data (2026.04.01). Confirm current participation with the provider before scheduling.
- Is Yiann Chen's NPI active?
- Yes — Yiann Chen's NPI (1891912689) is active in the NPPES registry as of the last update on 2021-12-09.
Source: CMS NPPES Data Dissemination (June 2026). NPI Central is not affiliated with CMS. Data is provided as-is from the public registry.