Stephen Masato Oishi, M.D.
Internal Medicine Physician · Honolulu, HI
Stephen Masato Oishi, M.D. is an internal medicine physician with a practice address in Honolulu, Hawaii, and NPI 1194813832, issued on Oct 10, 2006. Check the license (Hawaii MD-7480, as entered in NPPES) on the Hawaii Medical Board; the Medicare figures below come from public CMS files.
- Name
- Stephen Masato Oishi
- Credential
- M.D.
- Primary taxonomy
- Internal Medicine Physician 207R00000X
- License number
- MD-7480 HI
Self-reported in NPPES; status is on the state search - Practice location
- 321 N Kuakini St, Honolulu, HI 96817
- Phone
- (808) 523-8611
- Enumerated
- Oct 10, 2006
- Record last updated
- Jul 8, 2007 (not updated in 19 years: call before relying on the address or phone)
- Medicaid ID
- 06982701 HI
- Medicare enrollment
- Enrolled (PECOS I20100331000475); accepts Medicare assignment
- Medical or professional school
- Georgetown University School Of Medicine, 1984
- Telehealth
- Offers telehealth (CMS)
- Entity
- Type 1 · individual
8 nearest internal medicine physician records → All 902 in Hawaii → Look up another NPI →
Also registered at 321 N Kuakini St
A shared address usually means a shared clinic or building; it does not show who employs whom.
- Jared Acoba, M.D.Hematology & Oncology Physician1508889338
- Thomas Au, MDInternal Medicine Physician1184770463
- Timothy Au, M.D.Internal Medicine Physician1518287598
- Steven Azuma, M.D.Cardiovascular Disease Physician1518966233
- Arlene Baldillo, D.O.Obstetrics & Gynecology Physician1124234331
- Baron Ching, M.D.Internal Medicine Physician1003959065
Verify Stephen Masato Oishi in five checks
- 1IdentityNPI record in CMS NPPESNPI lookupConfirmed in NPPES
- 2LicenseActive license and public ordersHawaii Medical Board
Search for license MD-7480Check the board - 3Other statesLicenses and actions elsewhereDocInfo (FSMB)Not checked
- 4ExclusionsMedicare and Medicaid bansHHS-OIG exclusion listNot checked
- 5CertificationBoard certificationABMS AOA NCCPA AANPNot checked
57% more Medicare Part D claims than the average internal medicine physician in 2024
4,990 Medicare Part D claims for 426 beneficiaries, against an average of 3,176 among the 108,855 providers of this specialty who prescribed in Part D. Brand-name drugs were 16% of claims. 13 claims were for opioids.
Most prescribed
- Atorvastatin Calcium404 claims
- Rosuvastatin Calcium380 claims
- Amlodipine Besylate271 claims
- Losartan Potassium264 claims
- Simvastatin135 claims
- Telmisartan131 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: $81.66
3 payments; by number, the most common kind was food and beverage; the largest payer was AstraZeneca Pharmaceuticals LP. The 50,334 providers of this specialty with any payment received $1,303.06 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
- Queens University Medical GroupHonolulu, HI
Source: CMS Doctors and Clinicians National Downloadable File (the group practices a clinician bills Medicare through) (data.cms.gov).
Stephen Masato Oishi among 902 internal medicine physician records in Hawaii
Stephen Masato Oishi, M.D. is one of 902 internal medicine physician records with a practice address in Hawaii. 71% of them appear in a Medicare file (Part D prescribing, MIPS, Open Payments or Medicare group billing); this one does. Its NPI, issued in 2006, is newer than 4% of them.
- NPI issued2006 · 4% of these records are older, 55% newer
- In a Medicare fileYes · 71% of these records are
- In the CMS Doctors and Clinicians fileYes · 54% of these records are
- Graduated1984 · median 2001 among the 491 with a school on file
- Record last updated2007 · 63% of these records were not updated in five years or more
Source: CMS NPPES, file of Aug 9, 2026, every record with primary taxonomy 207R00000X and a Hawaii practice address; Medicare files: CMS Part D Prescribers 2024, MIPS 2023, Open Payments 2024, Doctors and Clinicians (data.cms.gov).
579 internal medicine physician records list a practice address in Honolulu
They are 579 of the 12,408 NPPES records with a practice address in Honolulu, and 902 internal medicine physician records in Hawaii.
All 902 in Hawaii → Every provider in Honolulu → Internal Medicine Physician nationwide →
The 8 internal medicine physician records with the nearest ZIP codes
- Julie Asari, M.D.Honolulu, HI 968171174520431
- Henry Cacanindin, M.D.Honolulu, HI 968171942253471
- Emilio Ganitano, M.D.Honolulu, HI 968171891740809
- Liang-Hsien Hahn, MD PHDHonolulu, HI 968171629028212
- Tad Iwanuma, M.D.Honolulu, HI 968171184600504
- Jonathan James, MDHonolulu, HI 968171366440901
- Lance Kagihara, MDHonolulu, HI 968171568411585
- Melanie Kelly, M.D.Honolulu, HI 968171982670154
Common questions
What is Stephen Masato Oishi, M.D.'s NPI number?
Stephen Masato Oishi, M.D.'s National Provider Identifier (NPI) is 1194813832, issued on Oct 10, 2006. An NPI identifies a provider in billing; it is not a license.
Where is Stephen Masato Oishi, M.D. located?
The NPPES record lists a practice address at 321 N Kuakini St, Honolulu, HI, 96817. Phone: (808) 523-8611. Providers update this record themselves, so call before visiting.
How can I verify Stephen Masato Oishi, M.D.'s license?
NPPES lists Hawaii license number MD-7480, as entered by the provider. Search the Hawaii Medical Board at https://cca.hawaii.gov/pvl/boards/medical/. The NPPES record confirms identity only; the state search shows license status, expiration and public orders.
How much does Stephen Masato Oishi, M.D. prescribe under Medicare Part D?
In 2024, Stephen Masato Oishi, M.D. had 4,990 Medicare Part D claims for 426 beneficiaries; the average among internal medicine physician prescribers was 3,176. 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.