NPPES file of Aug 9, 2026

Tammy T. Chang, M.D., PH.D.

Surgery Physician · San Francisco, CA

Tammy T. Chang, M.D., PH.D. is a surgery physician with a practice address in San Francisco, California, and NPI 1972787174, issued on Dec 24, 2007. Check the license (California A90279, 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 · method · Verify with CMS →

NPPES recordNPPES file of Aug 9, 2026
1972787174
Name
Tammy T. Chang
Credential
M.D., PH.D.
Primary taxonomy
Surgery Physician 208600000X
License number
A90279 CA
Self-reported in NPPES; status is on the state search
Practice location
513 Parnassus Ave, San Francisco, CA 94143
Phone
(415) 476-1239
Enumerated
Dec 24, 2007
Record last updated
Dec 24, 2007 (not updated in 19 years: call before relying on the address or phone)
Fax
(415) 502-1259
Medicare enrollment
Enrolled (PECOS I20100902000965); accepts Medicare assignment
Medical or professional school
Harvard Medical School, 2003
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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8 nearest surgery physician records → All 3,118 in California → Look up another NPI →

Also registered at 513 Parnassus Ave

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

  1. Kimiya Abtahi, DMDStudent in an Organized Health Care Education/Training Program1295397719
  2. Kemi Alabi, MDStudent in an Organized Health Care Education/Training Program1821857004
  3. Ivy Aslan, M.D.Specialist1346571833
  4. Su Aung, M.D.Infectious Disease Physician1649513805
  5. Jeanie Bhuller, D.O.Anesthesiology Physician1801020391
  6. Catherine Blebea, MDInternal Medicine Physician1134680531

Verify Tammy T. Chang in five checks

  1. 1IdentityNPI record in CMS NPPESNPI lookupConfirmed in NPPES
  2. 2LicenseActive license and public ordersMedical Board of California
    Search for license A90279    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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Bills Medicare through one group practice

  1. Ucsf Dept OF SurgerySan Francisco, CA

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

Tammy T. Chang among 3,118 surgery physician records in California

Tammy T. Chang, M.D., PH.D. is one of 3,118 surgery physician records with a practice address in California. 75% of them appear in a Medicare file (Part D prescribing, MIPS, Open Payments or Medicare group billing); this one does. Its NPI, issued in 2007, is newer than 45% of them.

  • NPI issued2007 · 45% of these records are older, 42% newer
  • In a Medicare fileYes · 75% of these records are
  • In the CMS Doctors and Clinicians fileYes · 61% of these records are
  • Graduated2003 · median 2003 among the 1,901 with a school on file
  • Record last updated2007 · 59% of these records were not updated in five years or more

Source: CMS NPPES, file of Aug 9, 2026, every record with primary taxonomy 208600000X and a California practice address; Medicare files: CMS Part D Prescribers 2024, MIPS 2023, Open Payments 2024, Doctors and Clinicians (data.cms.gov).

Surgery Physician providers in California

There are 3,118 surgery physician records in California.

All 3,118 in California → Every provider in San Francisco → Surgery Physician nationwide →

The 8 surgery physician records with the nearest ZIP codes

  1. Timothy Chuter, MDSan Francisco, CA 941431023074283
  2. Charles Eichler, MDSan Francisco, CA 941431265498729
  3. Sandy Feng, MDSan Francisco, CA 941431114981594
  4. Chris Freise, MDSan Francisco, CA 941431194780775
  5. Jessica Gosnell, MDSan Francisco, CA 941431053376590
  6. Scott Hansen, MDSan Francisco, CA 941431548224694
  7. Hobart Harris, MDSan Francisco, CA 941431174587208
  8. Dalbhir Jangra, MDSan Francisco, CA 941431144283854

Common questions

What is Tammy T. Chang, M.D., PH.D.'s NPI number?

Tammy T. Chang, M.D., PH.D.'s National Provider Identifier (NPI) is 1972787174, issued on Dec 24, 2007. An NPI identifies a provider in billing; it is not a license.

Where is Tammy T. Chang, M.D., PH.D. located?

The NPPES record lists a practice address at 513 Parnassus Ave, San Francisco, CA, 94143. Phone: (415) 476-1239. Providers update this record themselves, so call before visiting.

How can I verify Tammy T. Chang, M.D., PH.D.'s license?

NPPES lists California license number A90279, 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), 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.

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.