Warren Chang, MD
NPI 1083674550 · Nephrology Physician · Daly City, CA
Enrolled with Medicare as Practitioner - Nephrology · source: CMS PECOS Public Provider Enrollment (2026.04.01)
Warren Chang, MD is a Nephrology Physician provider in Daly City, CA (NPI 1083674550).
Provider details
- NPI number
- 1083674550
- Entity type
- Individual
- Primary specialty
- Nephrology PhysicianAllopathic & Osteopathic Physicians
- Credential
- MD
- Sex
- Male
- Sole proprietor
- Yes
- License
- AG9500 (CA)
Specialties & taxonomies
Allopathic & Osteopathic Physicians
Profile Score
A profile completeness & documented-activity index — NOT a quality, outcomes, or patient-satisfaction rating.
- Registry tenure25% of score
20 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
2,185 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) |
|---|---|---|
| Established Patient Office Or Other Outpatient Visit With Moderate Level of Decision Making, If Using Time, 30 Minutes Or More99214 | 407 | $150 |
| 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 | 380 | $18 |
| Subsequent Hospital Care With Moderate Levelof Medical Decision Making, If Using Time, at Least 35 Minutes99232 | 275 | $87 |
| Subsequent Hospital Care With Moderate Levelof Medical Decision Making, If Using Time, at Least 50 Minutes99233 | 208 | $132 |
| Dialysis Services, 4 Or More Physician Visits Per Month (20 Years Or Older)90960 | 162 | $400 |
What this provider prescribes (Medicare Part D)
Top drugs by Medicare Part D claim volume, 2024 · 46 distinct drugs on file.
| Drug | Part D claims (2024) | Beneficiaries |
|---|---|---|
| Dapagliflozin Propanediolbrand: Farxiga | 188 | 48 |
| Hydralazine Hcl | 177 | 49 |
| Amlodipine Besylate | 174 | 52 |
| Losartan Potassium | 124 | 42 |
| Furosemide | 89 | 28 |
| Parenteral Amino Acid 20% No.1brand: Prosol | 86 | — |
| Calcitriol | 86 |
Transparency — industry payments
Based on CMS Open Payments, 2024; not all care is captured.
$1,421 across 58 records (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
- 2006-03-27
- Last updated
- 2019-08-26
Frequently asked questions
- What is Warren Chang's NPI number?
- Warren Chang's National Provider Identifier (NPI) is 1083674550, a unique 10-digit ID issued by CMS for use in standard healthcare transactions.
- What is Warren Chang's specialty?
- Warren Chang is listed in the NPPES registry with a primary specialty of Nephrology Physician (Allopathic & Osteopathic Physicians).
- Where is Warren Chang located?
- Warren Chang's practice location on file with NPPES is 1498 Southgate Ave, Daly City, CA 94015-4015.
- What is Warren Chang's phone number?
- The practice phone number listed in the NPPES registry for Warren Chang is (650) 755-4492.
- Does Warren Chang accept Medicare?
- Warren Chang is approved to bill Medicare according to CMS PECOS enrollment data (2026.04.01). Confirm current participation with the provider before scheduling.
- Is Warren Chang's NPI active?
- Yes — Warren Chang's NPI (1083674550) is active in the NPPES registry as of the last update on 2019-08-26.
Source: CMS NPPES Data Dissemination (June 2026). NPI Central is not affiliated with CMS. Data is provided as-is from the public registry.