Matthew S. Chang, M.D.
Gastroenterology Physician · Palo Alto, CA
Matthew S. Chang, M.D. is a gastroenterology physician with a practice address in Palo Alto, California, and NPI 1598949521, issued on Dec 27, 2007. Check the license (California A133674, as entered in NPPES) on the Medical Board of California; the Medicare figures below come from public CMS files.
- Name
- Matthew S. Chang
- Credential
- M.D.
- Primary taxonomy
- Gastroenterology Physician 207RG0100X
- License numbers
- A133674 CA
250090 MA
245746 NY
Self-reported in NPPES; status is on the state search - Practice location
- 900 Blake Wilbur Dr, Palo Alto, CA 94304
- Phone
- (650) 736-5555
- Enumerated
- Dec 27, 2007
- Record last updated
- Dec 17, 2021 (not updated in 5 years: call before relying on the address or phone)
- Medicare enrollment
- Enrolled (PECOS I20150731016848); accepts Medicare assignment
- Medical or professional school
- University Of Michigan Medical School, 2006
- Entity
- Type 1 · individual
8 nearest gastroenterology physician records → All 2,140 in California → Look up another NPI →
Also registered at 900 Blake Wilbur Dr
A shared address usually means a shared clinic or building; it does not show who employs whom.
- Steven Binder, O.D.Optometrist1225172182
- Andrew Birkeland, M.D.Pediatric Otolaryngology Physician1700149317
- Eugene Carragee, M.D.Orthopaedic Surgery of the Spine Physician1881740355
- Joshua CarterRegistered Nurse1477419000
- Hyeun Sook Chon, NPNurse Practitioner1598217267
- Elisabeth Diver, M.D.Gynecologic Oncology Physician1467776948
Verify Matthew S. Chang in five checks
- 1IdentityNPI record in CMS NPPESNPI lookupConfirmed in NPPES
- 2LicenseActive license and public ordersMedical Board of California
Search for license A133674Check the board - 3Other statesLicenses and actions elsewhereDocInfo (FSMB)Not checked
- 4ExclusionsMedicare and Medicaid bansHHS-OIG exclusion listNot checked
- 5CertificationBoard certificationABMS AOA NCCPA AANPNot checked
24% fewer Medicare Part D claims than the average gastroenterology physician in 2024
616 Medicare Part D claims for 355 beneficiaries, against an average of 811 among the 16,445 providers of this specialty who prescribed in Part D. Brand-name drugs were 12% of claims.
Most prescribed
- Gavilyte-C239 claims
- Pantoprazole Sodium64 claims
- Xifaxan48 claims
- Ursodiol35 claims
- Carvedilol29 claims
- Furosemide21 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: $24.05
1 payment: food and beverage; the largest payer was Abbvie Inc. The 13,350 providers of this specialty with any payment received $5,015.95 on average. Payments are reported by manufacturers, not by the provider, and are not a sign of wrongdoing.
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
- Permanente Medical Group IncSan Francisco, CA
Source: CMS Doctors and Clinicians National Downloadable File (the group practices a clinician bills Medicare through) (data.cms.gov).
Matthew S. Chang among 2,140 gastroenterology physician records in California
Matthew S. Chang, M.D. 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 2007, is newer than 52% of them.
- NPI issued2007 · 52% of these records are older, 37% newer
- In a Medicare fileYes · 83% of these records are
- In the CMS Doctors and Clinicians fileYes · 72% of these records are
- Graduated2006 · median 2002 among the 1,538 with a school on file
- Record last updated2021 · 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.
All 2,140 in California → Every provider in Palo Alto → Gastroenterology Physician nationwide →
The 8 gastroenterology physician records with the nearest ZIP codes
- Ramsey Cheung, MDPalo Alto, CA 943041750394532
- John Clarke, M.D.Palo Alto, CA 943041467539643
- Tami Daugherty, M.D.Palo Alto, CA 943041194742064
- Samer Eldika, M.D.Palo Alto, CA 943041346267093
- Nielsen Fernandez-Becker, M.D., PH.D.Palo Alto, CA 943041972678639
- Harry Greenberg, MDPalo Alto, CA 943041689731200
- Peter Gregory, M.DPalo Alto, CA 943041891889903
- Joanne Imperial, MDPalo Alto, CA 943041225101884
Common questions
What is Matthew S. Chang, M.D.'s NPI number?
Matthew S. Chang, M.D.'s National Provider Identifier (NPI) is 1598949521, issued on Dec 27, 2007. An NPI identifies a provider in billing; it is not a license.
Where is Matthew S. Chang, M.D. located?
The NPPES record lists a practice address at 900 Blake Wilbur Dr, Palo Alto, CA, 94304. Phone: (650) 736-5555. Providers update this record themselves, so call before visiting.
How can I verify Matthew S. Chang, M.D.'s license?
NPPES lists California license number A133674, 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 Matthew S. Chang, M.D. prescribe under Medicare Part D?
In 2024, Matthew S. Chang, M.D. had 616 Medicare Part D claims for 355 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.