John Riordan, MD
NPI 1619040227 · Specialist · San Francisco, CA
Enrolled with Medicare as Practitioner - Nephrology · source: CMS PECOS Public Provider Enrollment (2026.04.01)
John Riordan, MD is a Specialist provider in San Francisco, CA (NPI 1619040227).
Provider details
- NPI number
- 1619040227
- Entity type
- Individual
- Primary specialty
- SpecialistOther Service Providers
- Credential
- MD
- Sex
- Male
- Sole proprietor
- No
- License
- A52155 (CA)
Specialties & taxonomies
Other Service Providers
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
1,433 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 50 Minutes99233 | 653 | $140 |
| Established Patient Office Or Other Outpatient Visit With Moderate Level of Decision Making, If Using Time, 30 Minutes Or More99214 | 302 | $162 |
| Initial Hospital Care With Moderate Level of Medical Decision Making, If Using Time, at Least 75 Minutes99223 | 148 | $205 |
| Dialysis Services, 2-3 Physician Visits Per Month (20 Years Or Older)90961 | 108 | $355 |
| Dialysis Services, 4 Or More Physician Visits Per Month (20 Years Or Older)90960 | 83 | $426 |
| Established Patient Office Or Other Outpatient Visit With Low Level OD Decision Making, If Using Time, 20 Minutes Or More99213 |
What this provider prescribes (Medicare Part D)
Top drugs by Medicare Part D claim volume, 2024 · 37 distinct drugs on file.
| Drug | Part D claims (2024) | Beneficiaries |
|---|---|---|
| Amlodipine Besylate | 148 | 48 |
| Losartan Potassium | 133 | 42 |
| Lisinopril | 76 | 27 |
| Dapagliflozin Propanediolbrand: Farxiga | 75 | 19 |
| Empagliflozinbrand: Jardiance | 71 | 21 |
| Sevelamer Carbonate | 58 | 22 |
| Furosemide |
Practice location
Mailing address
Registry dates
- Enumerated
- 2006-11-15
- Last updated
- 2022-07-29
- Certified
- 2022-07-29
Frequently asked questions
- What is John Riordan's NPI number?
- John Riordan's National Provider Identifier (NPI) is 1619040227, a unique 10-digit ID issued by CMS for use in standard healthcare transactions.
- What is John Riordan's specialty?
- John Riordan is listed in the NPPES registry with a primary specialty of Specialist (Other Service Providers).
- Where is John Riordan located?
- John Riordan's practice location on file with NPPES is 2100 Webster St, San Francisco, CA 94115-2377.
- What is John Riordan's phone number?
- The practice phone number listed in the NPPES registry for John Riordan is (415) 923-3815.
- Does John Riordan accept Medicare?
- John Riordan is approved to bill Medicare according to CMS PECOS enrollment data (2026.04.01). Confirm current participation with the provider before scheduling.
- Is John Riordan's NPI active?
- Yes — John Riordan's NPI (1619040227) is active in the NPPES registry as of the last update on 2022-07-29.
Source: CMS NPPES Data Dissemination (June 2026). NPI Central is not affiliated with CMS. Data is provided as-is from the public registry.