NPPES file of Aug 9, 2026

Steven Katznelson, M.D.

Internal Medicine Physician · San Francisco, CA

Steven Katznelson, M.D. is an internal medicine physician with a practice address in San Francisco, California, and NPI 1225059520, issued on Jul 21, 2006. Check the license (California G66893, as entered in NPPES) on the Medical Board of California; the Medicare figures below come from public CMS files.

Record from CMS NPPES, file of Aug 9, 2026 · Medicare files 2024 · method · Verify with CMS →

NPPES recordNPPES file of Aug 9, 2026
1225059520
Name
Steven Katznelson
Credential
M.D.
Primary taxonomy
Internal Medicine Physician 207R00000X
License number
G66893 CA
Self-reported in NPPES; status is on the state search
Practice location
2340 Clay St, San Francisco, CA 94115
Phone
(415) 923-6501
Enumerated
Jul 21, 2006
Record last updated
Jun 8, 2012 (not updated in 14 years: call before relying on the address or phone)
Medicare enrollment
Enrolled (PECOS I20100622000882); accepts Medicare assignment
Medical or professional school
University Of California, San Francisco School Of Medicine, 1988
Telehealth
Offers telehealth (CMS)
Entity
Type 1 · individual
Public record from CMS NPPES (open it on the CMS NPI Registry). Enrollment, assignment, school and telehealth: CMS Doctors and Clinicians file, Aug 2026. A record is not a license: verify it with the state board.
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Also registered at 2340 Clay St

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

  1. Nikhil Agarwal, M.D.Gastroenterology Physician1487831145
  2. Erin Akel, RN, FNPFamily Nurse Practitioner1629273461
  3. Kaylee Anderson, NPFamily Nurse Practitioner1528870045
  4. Gary Arsham, M.D.Internal Medicine Physician1487646758
  5. Janet Bellingham, MDTransplant Surgery Physician1508062431
  6. Marissa Benge, FNPFamily Nurse Practitioner1225483860

Verify Steven Katznelson in five checks

  1. 1IdentityNPI record in CMS NPPESNPI lookupConfirmed in NPPES
  2. 2LicenseActive license and public ordersMedical Board of California
    Search for license G66893
    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.

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75% fewer Medicare Part D claims than the average internal medicine physician in 2024

801 Medicare Part D claims for 191 beneficiaries, against an average of 3,176 among the 108,855 providers of this specialty who prescribed in Part D.

  1. Steven Katznelson801
  2. Specialty average3,176

Most prescribed

  1. Prednisone244 claims
  2. Pantoprazole Sodium55 claims
  3. Tacrolimus54 claims
  4. Valganciclovir Hcl53 claims
  5. Sulfamethoxazole-Trimethoprim48 claims
  6. Mycophenolate Mofetil32 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.

Industry payments in 2024: $15.07

1 payment: food and beverage; the largest payer was Merck Sharp & Dohme LLC. The 50,334 providers of this specialty with any payment received $1,303.06 on average. Payments are reported by manufacturers, not by the provider, and are not a sign of wrongdoing.

  1. Steven Katznelson$15.07
  2. Specialty average$1,303.06

Source: CMS Open Payments, program year 2024 (openpaymentsdata.cms.gov); average among providers of this specialty with at least one payment.

Bills Medicare through one group practice

  1. Sutter Bay Medical FoundationSan Francisco, CA

Source: CMS Doctors and Clinicians National Downloadable File (the group practices a clinician bills Medicare through) (data.cms.gov).

Steven Katznelson among 17,696 internal medicine physician records in California

Steven Katznelson, M.D. is one of 17,696 internal medicine physician records with a practice address in California. 79% 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 5% of them.

  • NPI issued2006 · 5% of these records are older, 56% newer
  • In a Medicare fileYes · 79% of these records are
  • In the CMS Doctors and Clinicians fileYes · 63% of these records are
  • Graduated1988 · median 2004 among the 11,065 with a school on file
  • Record last updated2012 · 61% of these records were not updated in five years or more

Source: CMS NPPES, file of Aug 9, 2026, every record with primary taxonomy 207R00000X and a California practice address; Medicare files: CMS Part D Prescribers 2024, MIPS 2023, Open Payments 2024, Doctors and Clinicians (data.cms.gov).

1,318 internal medicine physician records list a practice address in San Francisco

They are 1,318 of the 38,143 NPPES records with a practice address in San Francisco, and 17,696 internal medicine physician records in California.

The 8 internal medicine physician records with the nearest ZIP codes

  1. Gary Arsham, M.D.San Francisco, CA 941151487646758
  2. Richard Caplin, M.D.San Francisco, CA 941151568443455
  3. C Cooney, M.D.San Francisco, CA 941151255332094
  4. Sarita Dubey, MDSan Francisco, CA 941151316905466
  5. Meredith Heller, M.D.San Francisco, CA 941151073562096
  6. Alan Leung, MDSan Francisco, CA 941151245222330
  7. Susan Nguyen, MDSan Francisco, CA 941151164470696
  8. Daniel Null, MDSan Francisco, CA 941151689638744

Common questions

What is Steven Katznelson, M.D.'s NPI number?

Steven Katznelson, M.D.'s National Provider Identifier (NPI) is 1225059520, issued on Jul 21, 2006. An NPI identifies a provider in billing; it is not a license.

Where is Steven Katznelson, M.D. located?

The NPPES record lists a practice address at 2340 Clay St, San Francisco, CA, 94115. Phone: (415) 923-6501. Providers update this record themselves, so call before visiting.

How can I verify Steven Katznelson, M.D.'s license?

NPPES lists California license number G66893, 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.

How much does Steven Katznelson, M.D. prescribe under Medicare Part D?

In 2024, Steven Katznelson, M.D. had 801 Medicare Part D claims for 191 beneficiaries; the average among internal medicine physician prescribers was 3,176. Part D covers Medicare prescriptions 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. 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.