John Robert Nienow, MD
Internal Medicine (CMS) · San Francisco, CA
At a glance
2186 Geary Blvd Ste 314, San Francisco, CA 94115-3457
NPPES record updated May 6, 2025. Public records can lag behind changes at a practice.
Before you call: a quick checklist
- Are you accepting new patients?
- Do you accept my specific insurance plan?
- Do you provide the service I need at this address?
- Do I need a referral, and what is the earliest appointment?
Insurance participation and appointment availability are not established by these public records.
Medicare & insurance
This clinician has a currently effective opt-out record in the imported CMS file. Ask the practice about payment arrangements before booking.
- Effective Jan 1, 2026 through Jan 1, 2028
Source: Opt Out Affidavits : 2026-08-01 · Reporting period: 2026-08-01 to 2026-08-31 · Published Sep 21, 2026.
How to check your coverage
Use your plan’s provider directory or the member-services number on your insurance card. Confirm the clinician, practice address, service, and whether a referral is required. A missing opt-out record does not establish Medicare acceptance.
Check the official Medicare directory ↗Practice location
2186 Geary Blvd Ste 314San Francisco, CA 94115-3457
Additional reported practice locations
558 Clayton StPssb G500
San Francisco, CA 941172907
Phone: 4157461950
Fax: 4154319909
Education & affiliations
- Medical / professional school
- Yale University School Of Medicine
- Graduation year
- 1988
- CMS specialties
- Internal Medicine
Reported hospital affiliations
- California Pacific Medical Center - Mission Bernal San Francisco, CA
- California Pacific Medical Center- Van Ness Campus San Francisco, CA
- California Pacific Medical Ctr-Davies Campus Hosp San Francisco, CA
- Novato Community Hospital Novato, CA
- Ucsf Medical Center San Francisco, CA
Graduation year does not establish years in practice. A reported affiliation does not establish employment, current admitting privileges, or insurance participation.
Source: CMS National Downloadable File · Published Oct 15, 2026.
Source: CMS Facility Affiliation Data · Published Oct 15, 2026.
Procedures in the public data
Reported activity can help you ask more informed questions about a practice’s services.
No displayed procedure-category record in this release. This does not mean the clinician performs no procedures.
CMS uses a one-year claims window with a reporting lag. Counts cover the Medicare activity included by CMS, not all patients. “1–10” is a published range. Volume is not a quality or outcomes score. Coverage and methodology
Source: CMS Utilization Data · Published Oct 15, 2026.
Find providers with a similar service mix
Compare 2024 published Medicare activity in the same reported specialty, here or in another city.
Industry-reported general payments
Includes reported transfers of value, such as meals, travel, or consulting. Payments do not establish improper conduct or quality of care. Research funding and ownership values are excluded from this total.
See payment purposes and reporting companies
Reported purposes
| Purpose | Amount |
|---|---|
| Food and beverage | $1,868.57 |
Reporting companies
| Company | Amount |
|---|---|
| VIIV HEALTHCARE COMPANY | $722.71 |
| GILEAD SCIENCES, INC. | $629.19 |
| EMD SERONO, INC. | $516.67 |
Source: CMS 2025 payments grouped by covered recipient and nature of payments · Published Jun 30, 2026.
Professional details: NPI, taxonomy & registry record
Registry details
- Primary taxonomy
- Internal Medicine (CMS)
- Taxonomy code
- 207RI0200X
- Enumeration date
- Jan 18, 2006
- Record updated
- May 6, 2025
More registry details
- Provider type
- Individual · Type 1
- Reported credentials
- MD
Reported taxonomies and licenses
207RI0200X · Primary
License reported: 00G795490 CA
License numbers and credentials are reported to NPPES; HCPList does not independently verify them.
Practice location
2186 Geary Blvd Ste 314San Francisco, CA 94115-3457
- Phone
- (415) 202-1550
- Fax
- (415) 776-8233
Mailing address
2186 GEARY BLVD STE 314SAN FRANCISCO, CA 941153457
Information may be outdated or incomplete. Confirm details directly with the practice. HCPList is an independent directory and is not affiliated with CMS.
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