NPPES file of Aug 9, 2026

Ruth A. Armstrong, NP

Obstetrics & Gynecology Nurse Practitioner · San Francisco, CA

Ruth A. Armstrong, NP is an obstetrics & gynecology nurse practitioner with a practice address in San Francisco, California, and NPI 1558419291, issued on Jan 8, 2007. Check the license (California NPF11049, as entered in NPPES) with the California board that licenses this profession; the federal record below is the public data PlainDoctor holds for this provider.

Record from CMS NPPES, file of Aug 9, 2026 · method · Verify with CMS →

NPPES recordNPPES file of Aug 9, 2026
1558419291
Name
Ruth A. Armstrong
Credential
NP
Primary taxonomy
Obstetrics & Gynecology Nurse Practitioner 363LX0001X
License numbers
NPF11049 CA
RN320167 CA
Self-reported in NPPES; status is on the state search
Practice location
2727 Mariposa St Ste 100, San Francisco, CA 94110
Phone
(415) 437-3000
Enumerated
Jan 8, 2007
Record last updated
Sep 11, 2025
Fax
(415) 437-3050
Entity
Type 1 · individual
Public record from CMS NPPES (open it on the CMS NPI Registry). A record is not a license: verify it with the state board.
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8 nearest obstetrics & gynecology nurse practitioner records → All 394 in California → Look up another NPI →

Also registered at 2727 Mariposa St Ste 100

A shared address usually means a shared clinic or building; it does not show who employs whom.

  1. Simone BarberSocial Worker1881514099
  2. Pollyana ChaffeyMarriage & Family Therapist1962767475
  3. Brian Davis, FNPFamily Nurse Practitioner1871800318
  4. Jessica Dodge, PA-CPhysician Assistant1306963772
  5. Frank FernandezSpecialist1568338895
  6. Jon Dean GreenCounselor1235641762

Verify Ruth A. Armstrong in five checks

  1. 1IdentityNPI record in CMS NPPESNPI lookupConfirmed in NPPES
  2. 2LicenseActive license and public ordersWhich California board licenses this profession
    Search for license NPF11049    Check the board
  3. 3Other statesLicenses and actions elsewhereDocInfo (FSMB)Not checked
  4. 4ExclusionsMedicare and Medicaid bansHHS-OIG exclusion listNot checked
  5. 5CertificationBoard certificationABMS AOA NCCPA AANPNot checked
Find the California license search

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Ruth A. Armstrong among 394 obstetrics & gynecology nurse practitioner records in California

Ruth A. Armstrong, NP is one of 394 obstetrics & gynecology nurse practitioner records with a practice address in California. 38% of them appear in a Medicare file (Part D prescribing, MIPS, Open Payments or Medicare group billing); this one does not. Its NPI, issued in 2007, is newer than 38% of them.

  • NPI issued2007 · 38% of these records are older, 39% newer
  • In a Medicare fileNo · 38% of these records are
  • In the CMS Doctors and Clinicians fileNo · 14% of these records are
  • Record last updated2025 · 72% of these records were not updated in five years or more

Source: CMS NPPES, file of Aug 9, 2026, every record with primary taxonomy 363LX0001X and a California practice address; Medicare files: CMS Part D Prescribers 2024, MIPS 2023, Open Payments 2024, Doctors and Clinicians (data.cms.gov).

Obstetrics & Gynecology Nurse Practitioner providers in California

There are 394 obstetrics & gynecology nurse practitioner records in California. No Medicare prescribing, quality score, industry payment or hospital affiliation is published for this NPI.

All 394 in California → Every provider in San Francisco → Obstetrics & Gynecology Nurse Practitioner nationwide →

The 8 obstetrics & gynecology nurse practitioner records with the nearest ZIP codes

  1. Priscilla Abercrombie, NPSan Francisco, CA 941101154458859
  2. Margaret Hutchison, CNMSan Francisco, CA 941101841220324
  3. Michelle Johnston, CNMSan Francisco, CA 941101710916861
  4. Holly Kennedy, CNMSan Francisco, CA 941101619993714
  5. Susan Leibel, CNMSan Francisco, CA 941101083630180
  6. Susan Silberman, NPSan Francisco, CA 941101487701041
  7. Alexis Reiger, WHNPSan Francisco, CA 941111184123267
  8. Susannah Ewing, MSNSan Francisco, CA 941151013926435

Common questions

What is Ruth A. Armstrong, NP's NPI number?

Ruth A. Armstrong, NP's National Provider Identifier (NPI) is 1558419291, issued on Jan 8, 2007. An NPI identifies a provider in billing; it is not a license.

Where is Ruth A. Armstrong, NP located?

The NPPES record lists a practice address at 2727 Mariposa St Ste 100, San Francisco, CA, 94110. Phone: (415) 437-3000. Providers update this record themselves, so call before visiting.

How can I verify Ruth A. Armstrong, NP's license?

NPPES lists California license number NPF11049, as entered by the provider. Search the California board that licenses this profession; the NPPES record confirms identity only.

Source: CMS National Plan and Provider Enumeration System (NPPES), file of Aug 9, 2026 (NPPES files on CMS.gov); NUCC Health Care Provider Taxonomy. An NPI identifies who bills; it is not a license.

Written with AI tools from the named public files; every figure is computed from those files (how it is made).

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.