Registry data as of Aug 27, 2026

Nathan Bass, MD

Internal Medicine Physician · San Francisco, CA

Nathan Bass, MD is an internal medicine physician with a practice address in San Francisco, California, and NPI 1689638959, issued on Apr 13, 2006. Check the license (California A39874, as entered in NPPES) on the Medical Board of California; the federal record below is the public data PlainDoctor holds for this provider.

Record from CMS NPPES, loaded Aug 27, 2026 · method · Verify with CMS →

NPPES recordas of Aug 27, 2026
1689638959
Name
Nathan Bass
Credential
MD
Primary taxonomy
Internal Medicine Physician 207R00000X
License number
A39874 CA
Self-reported in NPPES; status is on the state search
Practice location
350 Parnassus Ave, San Francisco, CA 94143
Phone
(415) 353-2318
Enumerated
Apr 13, 2006
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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Also registered at 350 Parnassus Ave

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

  1. Karen Bagatelos, M.S.N.,N.P.Nurse Practitioner1780881045
  2. Nathan Becker, M.D.Endocrinology, Diabetes & Metabolism Physician1972696250
  3. Dwight Bissell, MDInternal Medicine Physician1831141241
  4. Michael Blum, MDInternal Medicine Physician1972568889
  5. Eric Buxton, M.D.Endocrinology, Diabetes & Metabolism Physician1134210362
  6. Jennifer Cademartori, NPFamily Nurse Practitioner1770504300

Verify Nathan Bass in five checks

  1. 1IdentityNPI record in CMS NPPESNPI lookupConfirmed in NPPES
  2. 2LicenseActive license and public ordersMedical Board of California
    Search for license A39874
    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
Open the California license search

PlainDoctor does not match the HHS-OIG exclusion list to individual records: most entries carry no NPI. Search the OIG exclusion list by name.

Statewide context: the Medical Board of California reported 374 disciplinary actions in FY 2022-23. California discipline data →

1,593 internal medicine physician records list a San Francisco practice address

They are 1,593 of the 38,143 NPPES records with a San Francisco practice address, and 20,403 internal medicine physician records in California. No Medicare prescribing, quality score, industry payment or hospital affiliation is published for this NPI.

Other internal medicine physician records in California

  1. Jacob Aaron, MDSan Francisco, CA1407202518
  2. Alistair Aaronson, MDStanford, CA1457628760
  3. Jose Abad., MDSacramento, CA1144607219
  4. Donna Abare, MDOakland, CA1386722155
  5. Marce AbareScotts Valley, CA1457744708
  6. Samuel Abarte, M.D.Chula Vista, CA1578535498
  7. Alexander Abary, MDLong Beach, CA1104995919
  8. Luba Abascal, MDSan Francisco, CA1023180874
  9. Michael Abate, MDSacramento, CA1548248131
  10. Wali Abawi, D.O.Joshua Tree, CA1104362268

Common questions

What is Nathan Bass, MD's NPI number?

Nathan Bass, MD's National Provider Identifier (NPI) is 1689638959, issued on Apr 13, 2006. An NPI identifies a provider in billing; it is not a license.

Where is Nathan Bass, MD located?

The NPPES record lists a practice address at 350 Parnassus Ave, San Francisco, CA, 94143. Phone: (415) 353-2318. Providers update this record themselves, so call before visiting.

How can I verify Nathan Bass, MD's license?

NPPES lists California license number A39874, as entered by the provider. Search the Medical Board of California at https://www.mbc.ca.gov/License-Verification/default.aspx. The NPPES record confirms identity only; the state search shows license status, expiration and public orders.

Source: CMS National Plan and Provider Enumeration System (NPPES), loaded Aug 27, 2026 (NPPES files on CMS.gov); NUCC Health Care Provider Taxonomy. An NPI identifies who bills; it is not a license.

Every figure on PlainDoctor is rendered directly from the federal CMS NPPES registry, Medicare Part D, MIPS, and Open Payments records, no number is typed in by an editor. See our editorial standards & corrections policy, the methodology behind these numbers, or report a data error. Data current as of Aug 27, 2026.