Derrick Siao, M.D.
Gastroenterology Physician · Santa Clara, CA
Derrick Siao, M.D. is a gastroenterology physician with a practice address in Santa Clara, California, and NPI 1073849261, issued on Oct 23, 2009. Check the license (California A110506, as entered in NPPES) on the Medical Board of California; the Medicare figures below come from public CMS files.
- Name
- Derrick Siao
- Credential
- M.D.
- Primary taxonomy
- Gastroenterology Physician 207RG0100X
- License number
- A110506 CA
Self-reported in NPPES; status is on the state search - Practice location
- 710 Lawrence Expy, Santa Clara, CA 95051
- Phone
- (408) 851-2750
- Enumerated
- Oct 23, 2009
- Record last updated
- Feb 11, 2022
- Medicare enrollment
- Enrolled (PECOS I20141007000204); accepts Medicare assignment
- Medical or professional school
- University Of Michigan Medical School, 2008
- Entity
- Type 1 · individual
8 nearest gastroenterology physician records → All 2,140 in California → Look up another NPI →
Also registered at 710 Lawrence Expy
A shared address usually means a shared clinic or building; it does not show who employs whom.
- Iype Abraham, M.D.Internal Medicine Physician1578737243
- Oren Abramson, MDPediatric Gastroenterology Physician1265511307
- Jamie Adiarte, PA-CPhysician Assistant1073824413
- Sarah Adut, PHDClinical Psychologist1609484831
- Najla Ahmadzia, M.D.Student in an Organized Health Care Education/Training Program1568692580
- Farhana Ahmed, MDHospitalist Physician1215110002
Verify Derrick Siao in five checks
- 1IdentityNPI record in CMS NPPESNPI lookupConfirmed in NPPES
- 2LicenseActive license and public ordersMedical Board of California
Search for license A110506Check the board - 3Other statesLicenses and actions elsewhereDocInfo (FSMB)Not checked
- 4ExclusionsMedicare and Medicaid bansHHS-OIG exclusion listNot checked
- 5CertificationBoard certificationABMS AOA NCCPA AANPNot checked
4% fewer Medicare Part D claims than the average gastroenterology physician in 2024
775 Medicare Part D claims for 392 beneficiaries, against an average of 811 among the 16,445 providers of this specialty who prescribed in Part D. Brand-name drugs were 19% of claims.
Most prescribed
- Gavilyte-C242 claims
- Pantoprazole Sodium128 claims
- Budesonide Dr72 claims
- Lubiprostone53 claims
- Mesalamine51 claims
- Cholestyramine31 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.
Bills Medicare through one group practice
- Permanente Medical Group IncSanta Clara, CA
Source: CMS Doctors and Clinicians National Downloadable File (the group practices a clinician bills Medicare through) (data.cms.gov).
Derrick Siao among 2,140 gastroenterology physician records in California
Derrick Siao, 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 2009, is newer than 69% of them.
- NPI issued2009 · 69% of these records are older, 28% newer
- In a Medicare fileYes · 83% of these records are
- In the CMS Doctors and Clinicians fileYes · 72% of these records are
- Graduated2008 · median 2002 among the 1,538 with a school on file
- Record last updated2022 · 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 Santa Clara → Gastroenterology Physician nationwide →
The 8 gastroenterology physician records with the nearest ZIP codes
- Michael Ahn, MDSanta Clara, CA 950511225115173
- Krisna Chai, M.D.Santa Clara, CA 950511013007202
- Caitlin Doan, MDSanta Clara, CA 950511285711135
- Spencer Fung, MDSanta Clara, CA 950511669559506
- Cary Kraft, M.D.Santa Clara, CA 950511740643493
- Dan Li, M.D.Santa Clara, CA 950511871757153
- Stephen Moff, MDSanta Clara, CA 950511093892945
- Joanna Ready, MDSanta Clara, CA 950511649357583
Common questions
What is Derrick Siao, M.D.'s NPI number?
Derrick Siao, M.D.'s National Provider Identifier (NPI) is 1073849261, issued on Oct 23, 2009. An NPI identifies a provider in billing; it is not a license.
Where is Derrick Siao, M.D. located?
The NPPES record lists a practice address at 710 Lawrence Expy, Santa Clara, CA, 95051. Phone: (408) 851-2750. Providers update this record themselves, so call before visiting.
How can I verify Derrick Siao, M.D.'s license?
NPPES lists California license number A110506, 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 Derrick Siao, M.D. prescribe under Medicare Part D?
In 2024, Derrick Siao, M.D. had 775 Medicare Part D claims for 392 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.