NPPES file of Aug 9, 2026

Kenneth J. Hammerman, MD

Gastroenterology Physician · San Francisco, CA

Kenneth J. Hammerman, MD is a gastroenterology physician with a practice address in San Francisco, California, and NPI 1174600365, issued on Nov 1, 2006. Check the license (California G25963, 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
1174600365
Name
Kenneth J. Hammerman
Credential
MD
Primary taxonomy
Gastroenterology Physician 207RG0100X
License number
G25963 CA
Self-reported in NPPES; status is on the state search
Practice location
1199 Bush Street, San Francisco, CA 94109
Phone
(415) 673-7600
Enumerated
Nov 1, 2006
Record last updated
Sep 11, 2025
Fax
(415) 673-8065
Medicaid ID
00G259630 CA
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 1199 Bush Street

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

  1. Clement Jones, MDOrthopaedic Surgery of the Spine Physician1245221373
  2. Lisa Kasalajtis, MDInternal Medicine Physician1225116569
  3. Sheena Kong, MDInternal Medicine Physician1790862993
  4. Diana Lam, MDCardiovascular Disease Physician1659455251
  5. Mark Oscherwitz, MDInternal Medicine Physician1437225059

Verify Kenneth J. Hammerman in five checks

  1. 1IdentityNPI record in CMS NPPESNPI lookupConfirmed in NPPES
  2. 2LicenseActive license and public ordersMedical Board of California
    Search for license G25963
    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

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82% fewer Medicare Part D claims than the average gastroenterology physician in 2024

142 Medicare Part D claims for 66 beneficiaries, against an average of 811 among the 16,445 providers of this specialty who prescribed in Part D. Brand-name drugs were 11% of claims.

  1. Kenneth Hammerman142
  2. Specialty average811

Most prescribed

  1. Atorvastatin Calcium18 claims
  2. Losartan Potassium15 claims
  3. Amlodipine Besylate14 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.

Kenneth J. Hammerman among 2,140 gastroenterology physician records in California

Kenneth J. Hammerman, MD is one of 2,140 gastroenterology physician records with a practice address in California. 83% 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 7% of them.

  • NPI issued2006 · 7% of these records are older, 48% newer
  • In a Medicare fileYes · 83% of these records are
  • In the CMS Doctors and Clinicians fileNo · 72% of these records are
  • Record last updated2025 · 60% of these records were not updated in five years or more

Source: CMS NPPES, file of Aug 9, 2026, every record with primary taxonomy 207RG0100X and a California practice address; Medicare files: CMS Part D Prescribers 2024, MIPS 2023, Open Payments 2024, Doctors and Clinicians (data.cms.gov).

Gastroenterology Physician providers in California

There are 2,140 gastroenterology physician records in California.

The 8 gastroenterology physician records with the nearest ZIP codes

  1. Kenneth Binmoeller, MDSan Francisco, CA 941091851321715
  2. Christina Chou, MDSan Francisco, CA 941091164749628
  3. Richard Frederick, M.D.San Francisco, CA 941091720009160
  4. Thomas Haddad, M.D.San Francisco, CA 941091932151867
  5. Christopher Hamerski, M.D.San Francisco, CA 941091205033420
  6. Mimi Lin, M.D.San Francisco, CA 941091659588457
  7. Jagrati Mathur, MDSan Francisco, CA 941091205000734
  8. Andrew Nett, M.D.San Francisco, CA 941091871720581

Common questions

What is Kenneth J. Hammerman, MD's NPI number?

Kenneth J. Hammerman, MD's National Provider Identifier (NPI) is 1174600365, issued on Nov 1, 2006. An NPI identifies a provider in billing; it is not a license.

Where is Kenneth J. Hammerman, MD located?

The NPPES record lists a practice address at 1199 Bush Street, San Francisco, CA, 94109. Phone: (415) 673-7600. Providers update this record themselves, so call before visiting.

How can I verify Kenneth J. Hammerman, MD's license?

NPPES lists California license number G25963, 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 Kenneth J. Hammerman, MD prescribe under Medicare Part D?

In 2024, Kenneth J. Hammerman, MD had 142 Medicare Part D claims for 66 beneficiaries; the average among gastroenterology physician prescribers was 811. 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.