Tammy Chang, M.D., PH.D.
NPI 1972787174 · Surgery Physician · San Francisco, CA
Enrolled with Medicare as Practitioner - General Surgery · source: CMS PECOS Public Provider Enrollment (2026.04.01)
Tammy Chang, M.D., PH.D. is a Surgery Physician provider in San Francisco, CA (NPI 1972787174).
Provider details
- NPI number
- 1972787174
- Entity type
- Individual
- Primary specialty
- Surgery PhysicianAllopathic & Osteopathic Physicians
- Credential
- M.D., PH.D.
- Sex
- Female
- Sole proprietor
- No
- License
- A90279 (CA)
Specialties & taxonomies
Allopathic & Osteopathic Physicians
Profile Score
A profile completeness & documented-activity index — NOT a quality, outcomes, or patient-satisfaction rating.
- Registry tenure28% of score
18 yrs in NPPES registry
- Profile completeness28% of score
100% of core fields populated
- Practice footprint17% of score
1 documented practice location
- Medicare service volume (vs. specialty peers)28% of score
84 Medicare services, 2024 (ranked within specialty)
Medicare volume is ranked against active providers in the same specialty. Signals a provider has no public data for (e.g. Medicare claims) are left out of the score entirely — never counted as zero — so providers without that data are not penalized. See the full formula and weights in our methodology.
What this provider does (Medicare)
Based on Medicare fee-for-service claims, 2024; not all care is captured.
| Service (HCPCS) | Medicare services | Typical Medicare-allowed (2024) |
|---|---|---|
| Insertion of Central Venous Tube With Port (5 Years Or Older)36561 | 23 | $372 |
| Fluoroscopic Guidance for Insertion Or Removal of Central Vein Access Device77001 | 22 | $19 |
| Ultrasonic Guidance for Blood Vessel Access76937 | 21 | $15 |
| Use of a Drug to Induce Depression of Consciousness By Physician Performing a Procedure (5 Years Or Older), Initial 15 Minutes99152 | 18 | $13 |
Typical Medicare-allowed amounts for these services range $13–$372 (2024). The Medicare-allowed amount is what Medicare recognizes for a service under fee-for-service — a reference figure for 2024, not a price quote and not what you would be billed. Medicare Part B covers roughly an eighth of all NPIs (65+ skew); services with fewer than 11 beneficiaries are suppressed by CMS. Source: CMS Medicare Physician & Other Practitioners, by Provider & Service.
Practice location
Mailing address
Registry dates
- Enumerated
- 2007-12-24
- Last updated
- 2007-12-24
Frequently asked questions
- What is Tammy Chang's NPI number?
- Tammy Chang's National Provider Identifier (NPI) is 1972787174, a unique 10-digit ID issued by CMS for use in standard healthcare transactions.
- What is Tammy Chang's specialty?
- Tammy Chang is listed in the NPPES registry with a primary specialty of Surgery Physician (Allopathic & Osteopathic Physicians).
- Where is Tammy Chang located?
- Tammy Chang's practice location on file with NPPES is 513 Parnassus Ave, San Francisco, CA 94143-0470.
- What is Tammy Chang's phone number?
- The practice phone number listed in the NPPES registry for Tammy Chang is (415) 476-1239.
- Does Tammy Chang accept Medicare?
- Tammy Chang is approved to bill Medicare according to CMS PECOS enrollment data (2026.04.01). Confirm current participation with the provider before scheduling.
- Is Tammy Chang's NPI active?
- Yes — Tammy Chang's NPI (1972787174) is active in the NPPES registry as of the last update on 2007-12-24.
Source: CMS NPPES Data Dissemination (June 2026). NPI Central is not affiliated with CMS. Data is provided as-is from the public registry.