Fabio Massaiti Iwamoto, MD
Neurology Physician · Stanford, CA
Fabio Massaiti Iwamoto, MD is a neurology physician with a practice address in Stanford, California, and NPI 1053623934, issued on Jul 8, 2010. Check the license on the Medical Board of California; the Medicare figures below come from public CMS files.
- Name
- Fabio Massaiti Iwamoto
- Credential
- MD
- Primary taxonomy
- Neurology Physician 2084N0400X
- License number
- 264009 NY
Self-reported in NPPES; status is on the state search - Practice location
- 300 Pasteur Dr, Stanford, CA 94305
- Phone
- (650) 723-4000
- Enumerated
- Jul 8, 2010
- Record last updated
- Jul 2, 2026
- Medicare enrollment
- Enrolled (PECOS I20120307000091); accepts Medicare assignment
- Telehealth
- Offers telehealth (CMS)
- Entity
- Type 1 · individual
8 nearest neurology physician records → All 2,339 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 Fabio Massaiti Iwamoto in five checks
- 1IdentityNPI record in CMS NPPESNPI lookupConfirmed in NPPES
- 2LicenseActive license and public ordersMedical Board of CaliforniaCheck the board
- 3Other statesLicenses and actions elsewhereDocInfo (FSMB)Not checked
- 4ExclusionsMedicare and Medicaid bansHHS-OIG exclusion listNot checked
- 5CertificationBoard certificationABMS AOA NCCPA AANPNot checked
95% fewer Medicare Part D claims than the average neurology physician in 2024
73 Medicare Part D claims for 28 beneficiaries, against an average of 1,370 among the 15,005 providers of this specialty who prescribed in Part D.
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.
The MIPS final score for 2023 (Medicare payment program): 100 of 100
The Merit-based Incentive Payment System score is reported for this clinician. Four categories are weighted into the final score; the average among 454,083 clinicians with a measured score was 83.5.
Source: CMS Quality Payment Program, MIPS performance year 2023; category weights for 2023 (qpp.cms.gov).
Industry payments in 2024: $9,244.07
7 payments; by number, the most common kind was travel and lodging; the largest payer was F. Hoffmann-La Roche AG. The 10,858 providers of this specialty with any payment received $8,318.07 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
- Trustees OF Columbia University IN The City OF New YorkNew York, NY
Source: CMS Doctors and Clinicians National Downloadable File (the group practices a clinician bills Medicare through) (data.cms.gov).
Fabio Massaiti Iwamoto among 2,339 neurology physician records in California
Fabio Massaiti Iwamoto, MD is one of 2,339 neurology physician records with a practice address in California. 81% of them appear in a Medicare file (Part D prescribing, MIPS, Open Payments or Medicare group billing); this one does. Its NPI, issued in 2010, is newer than 61% of them.
- NPI issued2010 · 61% of these records are older, 36% newer
- In a Medicare fileYes · 81% of these records are
- In the CMS Doctors and Clinicians fileYes · 70% of these records are
- Graduated1999 · median 2006 among the 1,628 with a school on file
- Record last updated2026 · 55% of these records were not updated in five years or more
Source: CMS NPPES, file of Aug 9, 2026, every record with primary taxonomy 2084N0400X and a California practice address; Medicare files: CMS Part D Prescribers 2024, MIPS 2023, Open Payments 2024, Doctors and Clinicians (data.cms.gov).
78 neurology physician records list a practice address in Stanford
They are 78 of the 5,606 NPPES records with a practice address in Stanford, and 2,339 neurology physician records in California.
All 2,339 in California → Every provider in Stanford → Neurology Physician nationwide →
The 8 neurology physician records with the nearest ZIP codes
- Sheena Aurora, MBBSStanford, CA 943051346303716
- Leslie Dorfman, MDStanford, CA 943051255382065
- Jeffrey Dunn, MDStanford, CA 943051639123383
- Erik Ensrud, MDStanford, CA 943051982658738
- Anna Finley Caulfield, M.D.Stanford, CA 943051851358097
- Hideki Garren, MDStanford, CA 943051407807183
- Michael Greicius, MDStanford, CA 943051861443509
- Frank Longo, MD, PHDStanford, CA 943051801966254
Common questions
What is Fabio Massaiti Iwamoto, MD's NPI number?
Fabio Massaiti Iwamoto, MD's National Provider Identifier (NPI) is 1053623934, issued on Jul 8, 2010. An NPI identifies a provider in billing; it is not a license.
Where is Fabio Massaiti Iwamoto, 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 Fabio Massaiti Iwamoto, MD's license?
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 Fabio Massaiti Iwamoto, MD prescribe under Medicare Part D?
In 2024, Fabio Massaiti Iwamoto, MD had 73 Medicare Part D claims for 28 beneficiaries; the average among neurology physician prescribers was 1,370. Part D covers Medicare prescriptions only.
What is Fabio Massaiti Iwamoto, MD's MIPS final score?
The 2023 MIPS final score is 100 of 100. The average among 454,083 clinicians with a measured score was 83.5.
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.