Provider records sourced from NPPES (CMS National Plan & Provider Enumeration System). Data current as of October 4, 2026.
NPIDirectory

Dr. John Robert Nienow, MD

Individual provider Infectious Disease Physician · NPI 1861472649

Dr. John Robert Nienow, MD practises Internal Medicine in San Francisco, California. Graduated from Yale University School of Medicine in 1988, 38 years ago. Works from 2 locations and accepts Medicare assignment. Licensed in California.

Years since qualifying
38
Trained at
Yale University School of Medicine
Licensed in
CA
In the registry since
2006
What do these letters mean?
MD — Doctor of Medicine
A physician who completed allopathic medical school.

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Practice location Address checks out

2186 Geary Blvd Ste 314
San Francisco, CA 94115-3457
Phone: (415) 202-1550
Fax: (415) 776-8233
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Pin is approximate — placed at the ZIP-code centre, not the exact door.

Additional practice locations (1)

  • 558 Clayton St, San Francisco, CA 94117-2907 — (415) 746-1950

Specialties & licences

Infectious Disease Physician (primary) Taxonomy 207RI0200X · Licence 00G795490 (CA)

Record details

NPI number1861472649
Entity typeIndividual (Type 1)
GenderMale
Credentials MD
Sole proprietorNo
NPI enumeratedJanuary 18, 2006
Last updated in NPPESMay 6, 2025
Certification dateMay 6, 2025

Medicare enrollment

From the CMS Doctors & Clinicians file — this clinician is enrolled in Medicare.

Medicare specialtyINTERNAL MEDICINE
Medical schoolYALE UNIVERSITY SCHOOL OF MEDICINE
Graduated 1988 (38 years in practice)
Accepts Medicare assignment Yes — accepts the Medicare-approved amount

Medicare patients and services, 2024

From the CMS Medicare Physician & Other Practitioners file for calendar year 2024. It counts Original Medicare patients only, so a practice that mostly sees Medicare Advantage or privately insured patients looks smaller here than it is.

Medicare patients192
Services billed 1,051 a service is one billed item, such as a visit, a test or a procedure
Average patient age71

Dollar amounts are not shown. What Medicare pays a practice is gross billings, before staff, premises and tax and including the cost of any drugs it administers, so it is not what a clinician earns.

Payments from drug and device companies, 2025

Drug and device makers are required by federal law (the Physician Payments Sunshine Act) to report what they pay or give to clinicians, and CMS publishes the reports as Open Payments. This is the 2025 program year. A report is a record of a payment, not an allegation of anything, and many are small items such as meals. Only general payments are listed here; research payments and ownership or investment interests are reported separately by CMS and are not shown.

Food and Beverage $1,869 103 payments · a meal or drink at a meeting or visit, not a fee

Each amount is the sum of what companies reported for that kind of payment in 2025, rounded to the dollar. Not all of it is income to the clinician: a meal is not a fee, a charitable contribution goes to a charity, and a royalty or an acquisition payment is not a salary.

Check a report, or dispute one, at the source in CMS’s own tool, Open Payments. Corrections go through CMS’s dispute process. This site removes a home address on request and asks for no proof, because that is privacy; it will not remove an accurate payment report on request, because that is a statutory public disclosure.

Practises at

Facilities the CMS Facility Affiliation file lists for this clinician. Those with a page here are linked.

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