Howard Cooper Masuoka, MD
Gastroenterology Physician · Stanford, CA
Howard Cooper Masuoka, MD is a gastroenterology physician with a practice address in Stanford, California, and NPI 1770630162, issued on Jan 5, 2007. Check the license (California C184254, as entered in NPPES) on the Medical Board of California; the Medicare figures below come from public CMS files.
- Name
- Howard Cooper Masuoka
- Credential
- MD
- Primary taxonomy
- Gastroenterology Physician 207RG0100X
- License numbers
- C184254 CA
01069938A IN
Self-reported in NPPES; status is on the state search - Practice location
- 300 Pasteur Dr, Stanford, CA 94305
- Phone
- (650) 723-4000
- Enumerated
- Jan 5, 2007
- Record last updated
- Feb 6, 2025
- Medicaid IDs
- 201029030 IN
440002000 MN - Medicare enrollment
- Enrolled (PECOS I20110817000348); accepts Medicare assignment
- Telehealth
- Offers telehealth (CMS)
- Entity
- Type 1 · individual
8 nearest gastroenterology physician records → All 2,140 in California → Look up another NPI →
Also registered at 300 Pasteur Dr
A shared address usually means a shared clinic or building; it does not show who employs whom.
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Verify Howard Cooper Masuoka in five checks
- 1IdentityNPI record in CMS NPPESNPI lookupConfirmed in NPPES
- 2LicenseActive license and public ordersMedical Board of California
Search for license C184254Check the board - 3Other statesLicenses and actions elsewhereDocInfo (FSMB)Not checked
- 4ExclusionsMedicare and Medicaid bansHHS-OIG exclusion listNot checked
- 5CertificationBoard certificationABMS AOA NCCPA AANPNot checked
60% fewer Medicare Part D claims than the average gastroenterology physician in 2024
328 Medicare Part D claims for 126 beneficiaries, against an average of 811 among the 16,445 providers of this specialty who prescribed in Part D. Brand-name drugs were 22% of claims.
Most prescribed
- Ursodiol32 claims
- Peg 3350-Electrolyte30 claims
- Tenofovir Disoproxil Fumarate28 claims
- Furosemide19 claims
- Amiloride Hcl18 claims
- Lactulose16 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.
2 hospitals and group practices
- IU Health Medical Group LLCIndianapolis, IN
- Margaret Mary Community Hospital IncBatesville, IN · Critical Access Hospitals
Source: CMS Doctors and Clinicians National Downloadable File (the group practices a clinician bills Medicare through); hospitals matched to CMS Hospital General Information (Care Compare) (data.cms.gov).
Howard Cooper Masuoka among 2,140 gastroenterology physician records in California
Howard Cooper Masuoka, MD 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
- Graduated2003 · median 2002 among the 1,538 with a school on file
- Record last updated2025 · 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).
70 gastroenterology physician records list a practice address in Stanford
They are 70 of the 5,606 NPPES records with a practice address in Stanford, and 2,140 gastroenterology physician records in California.
All 2,140 in California → Every provider in Stanford → Gastroenterology Physician nationwide →
The 8 gastroenterology physician records with the nearest ZIP codes
- Aijaz Ahmed, MDStanford, CA 943051447351747
- Ashish Atreja, MDStanford, CA 943051831152883
- Ann Chen, MDStanford, CA 943051003840307
- Shai Friedland, M.D.Stanford, CA 943051316034655
- Jeffrey Glenn, M.D., PH.D.Stanford, CA 943051366523946
- Joo Hwang, MDStanford, CA 943051194815043
- Paul Kwo, M.D.Stanford, CA 943051578527008
- Uri Ladabaum, MDStanford, CA 943051245288059
Common questions
What is Howard Cooper Masuoka, MD's NPI number?
Howard Cooper Masuoka, MD's National Provider Identifier (NPI) is 1770630162, issued on Jan 5, 2007. An NPI identifies a provider in billing; it is not a license.
Where is Howard Cooper Masuoka, MD located?
The NPPES record lists a practice address at 300 Pasteur Dr, Stanford, CA, 94305. Phone: (650) 723-4000. Providers update this record themselves, so call before visiting.
How can I verify Howard Cooper Masuoka, MD's license?
NPPES lists California license number C184254, 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 Howard Cooper Masuoka, MD prescribe under Medicare Part D?
In 2024, Howard Cooper Masuoka, MD had 328 Medicare Part D claims for 126 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.