John W. Riordan, MD
Specialist · San Francisco, CA
John W. Riordan, MD is a specialist with a practice address in San Francisco, California, and NPI 1619040227, issued on Nov 15, 2006. Check the license (California A52155, as entered in NPPES) with the California board that licenses this profession; the Medicare figures below come from public CMS files.
- Name
- John W. Riordan
- Credential
- MD
- Primary taxonomy
- Specialist 174400000X
- License number
- A52155 CA
Self-reported in NPPES; status is on the state search - Practice location
- 2100 Webster St, San Francisco, CA 94115
- Phone
- (415) 923-3815
- Enumerated
- Nov 15, 2006
- Record last updated
- Jul 29, 2022
- Fax
- (415) 749-5713
- Medicaid ID
- 00A521550 CA
- Medicare enrollment
- Enrolled (PECOS I20080430000339); accepts Medicare assignment
- Medical or professional school
- University Of Texas Medical Branch At Galveston, 1987
- Telehealth
- Offers telehealth (CMS)
- Entity
- Type 1 · individual
8 nearest specialist records → All 5,749 in California → Look up another NPI →
Also registered at 2100 Webster St
A shared address usually means a shared clinic or building; it does not show who employs whom.
- Arthur Allen, MDOphthalmology Physician1255332334
- Anait Ambarian, ODOptometrist1992032411
- Peter Anastassiou, M.D.Thoracic Surgery (Cardiothoracic Vascular Surgery) Physician1912904806
- William Andereck, M.D.Internal Medicine Physician1699800219
- Jennifer Austin, LCSWClinical Social Worker1669878492
- Amy Baertson, R.DRegistered Dietitian1598914202
Verify John W. Riordan in five checks
- 1IdentityNPI record in CMS NPPESNPI lookupConfirmed in NPPES
- 2LicenseActive license and public ordersWhich California board licenses this profession
Search for license A52155Check the board - 3Other statesLicenses and actions elsewhereDocInfo (FSMB)Not checked
- 4ExclusionsMedicare and Medicaid bansHHS-OIG exclusion listNot checked
- 5CertificationBoard certificationABMS AOA NCCPA AANPNot checked
4% more Medicare Part D claims than the average specialist in 2024
1,433 Medicare Part D claims for 226 beneficiaries, against an average of 1,380 among the 8,233 providers of this specialty who prescribed in Part D. Brand-name drugs were 22% of claims.
Most prescribed
- Amlodipine Besylate148 claims
- Losartan Potassium133 claims
- Lisinopril76 claims
- Farxiga75 claims
- Jardiance71 claims
- Sevelamer Carbonate58 claims
Source: CMS Medicare Part D Prescribers by Provider and Drug, 2024 (data.cms.gov). Part D covers prescriptions for Medicare patients only; drugs with fewer than 11 claims are not published.
The practice group's MIPS final score for 2023 (Medicare payment program): 92.8 of 100
The Merit-based Incentive Payment System score is reported for the practice group, not for one clinician alone. Four categories are weighted into the final score; the average among 454,083 clinicians with a measured score was 83.5.
Source: CMS Quality Payment Program, MIPS performance year 2023, group reporting; category weights for 2023 (qpp.cms.gov).
Bills Medicare through one group practice
- Renal Medical AssociatesSan Francisco, CA
Source: CMS Doctors and Clinicians National Downloadable File (the group practices a clinician bills Medicare through) (data.cms.gov).
John W. Riordan among 5,749 specialist records in California
John W. Riordan, MD is one of 5,749 specialist records with a practice address in California. 30% of them appear in a Medicare file (Part D prescribing, MIPS, Open Payments or Medicare group billing); this one does. Its NPI, issued in 2006, is newer than 7% of them.
- NPI issued2006 · 7% of these records are older, 60% newer
- In a Medicare fileYes · 30% of these records are
- In the CMS Doctors and Clinicians fileYes · 19% of these records are
- Graduated1987 · median 1989 among the 1,075 with a school on file
- Record last updated2022 · 77% of these records were not updated in five years or more
Source: CMS NPPES, file of Aug 9, 2026, every record with primary taxonomy 174400000X and a California practice address; Medicare files: CMS Part D Prescribers 2024, MIPS 2023, Open Payments 2024, Doctors and Clinicians (data.cms.gov).
666 specialist records list a practice address in San Francisco
They are 666 of the 38,143 NPPES records with a practice address in San Francisco, and 5,749 specialist records in California.
All 5,749 in California → Every provider in San Francisco → Specialist nationwide →
The 8 specialist records with the nearest ZIP codes
- Barry Baron, MDSan Francisco, CA 941151467563353
- Ari Baron, M.D.San Francisco, CA 941151013086420
- Kristoffer Chang, M.D.San Francisco, CA 941151790761336
- Carolyn Cooper, M.D.San Francisco, CA 941151518010560
- Frank Farrell, M.D.San Francisco, CA 941151891770905
- Gary Feldman, M.D.San Francisco, CA 941151336220854
- Kathleen Grant, M.D.San Francisco, CA 941151538238548
- Sonya KashyapSan Francisco, CA 941151457444184
Common questions
What is John W. Riordan, MD's NPI number?
John W. Riordan, MD's National Provider Identifier (NPI) is 1619040227, issued on Nov 15, 2006. An NPI identifies a provider in billing; it is not a license.
Where is John W. Riordan, MD located?
The NPPES record lists a practice address at 2100 Webster St, San Francisco, CA, 94115. Phone: (415) 923-3815. Providers update this record themselves, so call before visiting.
How can I verify John W. Riordan, MD's license?
NPPES lists California license number A52155, as entered by the provider. Search the California board that licenses this profession; the NPPES record confirms identity only.
How much does John W. Riordan, MD prescribe under Medicare Part D?
In 2024, John W. Riordan, MD had 1,433 Medicare Part D claims for 226 beneficiaries; the average among specialist prescribers was 1,380. Part D covers Medicare prescriptions only.
What is John W. Riordan, MD's MIPS final score?
The 2023 MIPS final score is 92.8 of 100, reported for the practice group. The average among 454,083 clinicians with a measured score was 83.5.
Source: CMS National Plan and Provider Enumeration System (NPPES), file of Aug 9, 2026 (NPPES files on CMS.gov); NUCC Health Care Provider Taxonomy. Medicare files from data.cms.gov. An NPI identifies who bills; it is not a license.
Figures on PlainDoctor are read from the federal files each page names (CMS NPPES, Medicare Part D, MIPS, Open Payments; the HHS-OIG exclusion list only as counts) and from Census population estimates, with the file date shown beside them. See our editorial standards & corrections policy, the methodology behind these numbers, or report a data error. Data current as of Aug 9, 2026.