Matthew Chang, M.D.
NPI 1598949521 · Gastroenterology Physician · Palo Alto, CA
Enrolled with Medicare as Practitioner - Gastroenterology · source: CMS PECOS Public Provider Enrollment (2026.04.01)
Matthew Chang, M.D. is a Gastroenterology Physician provider in Palo Alto, CA (NPI 1598949521).
Provider details
- NPI number
- 1598949521
- Entity type
- Individual
- Primary specialty
- Gastroenterology PhysicianAllopathic & Osteopathic Physicians
- Credential
- M.D.
- Sex
- Male
- Sole proprietor
- No
- License
- 250090 (MA)
Specialties & taxonomies
Allopathic & Osteopathic Physicians
Allopathic & Osteopathic Physicians
Allopathic & Osteopathic Physicians
Profile Score
A profile completeness & documented-activity index — NOT a quality, outcomes, or patient-satisfaction rating.
- Registry tenure33% of score
18 yrs in NPPES registry
- Profile completeness33% of score
100% of core fields populated
- Practice footprint20% of score
1 documented practice location
- Open Payments transparency13% of score
Has Open Payments disclosures (2024)
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 prescribes (Medicare Part D)
Top drugs by Medicare Part D claim volume, 2024 · 10 distinct drugs on file.
| Drug | Part D claims (2024) | Beneficiaries |
|---|---|---|
| Peg3350/Sod Sulf,bicarb,cl/Kclbrand: Gavilyte-C | 239 | 235 |
| Pantoprazole Sodium | 64 | 37 |
| Rifaximinbrand: Xifaxan | 48 | — |
| Ursodiol | 35 | 15 |
| Carvedilol | 29 | 17 |
| Furosemide | 21 | — |
| Spironolactone | 19 | — |
Transparency — industry payments
Based on CMS Open Payments, 2024; not all care is captured.
$24 across 1 record (Open Payments 2024)
Open Payments discloses payments and transfers of value (meals, travel, consulting, research, royalties) from drug and device makers to providers. This is a transparency signal, not a verdict — such payments are legal and common, and their presence is neither an endorsement nor a criticism. Source: CMS Open Payments, program year 2024.
Practice location
Mailing address
Registry dates
- Enumerated
- 2007-12-27
- Last updated
- 2021-12-17
Frequently asked questions
- What is Matthew Chang's NPI number?
- Matthew Chang's National Provider Identifier (NPI) is 1598949521, a unique 10-digit ID issued by CMS for use in standard healthcare transactions.
- What is Matthew Chang's specialty?
- Matthew Chang is listed in the NPPES registry with a primary specialty of Gastroenterology Physician (Allopathic & Osteopathic Physicians).
- Where is Matthew Chang located?
- Matthew Chang's practice location on file with NPPES is 900 Blake Wilbur Dr, Palo Alto, CA 94304-2201.
- What is Matthew Chang's phone number?
- The practice phone number listed in the NPPES registry for Matthew Chang is (650) 736-5555.
- Does Matthew Chang accept Medicare?
- Matthew Chang is approved to bill Medicare according to CMS PECOS enrollment data (2026.04.01). Confirm current participation with the provider before scheduling.
- Is Matthew Chang's NPI active?
- Yes — Matthew Chang's NPI (1598949521) is active in the NPPES registry as of the last update on 2021-12-17.
Source: CMS NPPES Data Dissemination (June 2026). NPI Central is not affiliated with CMS. Data is provided as-is from the public registry.