NPPES file of Aug 9, 2026

Ronald Y. Yamaguchi, MD

Urology Physician · Santa Clara, CA

Ronald Y. Yamaguchi, MD is a urology physician with a practice address in Santa Clara, California, and NPI 1104905843, issued on Nov 3, 2006. Check the license (California G79384, as entered in NPPES) on the Medical Board of California; the Medicare figures below come from public CMS files.

Record from CMS NPPES, file of Aug 9, 2026 · Medicare files 2024 · method · Verify with CMS →

NPPES recordNPPES file of Aug 9, 2026
1104905843
Name
Ronald Y. Yamaguchi
Credential
MD
Primary taxonomy
Urology Physician 208800000X
License number
G79384 CA
Self-reported in NPPES; status is on the state search
Practice location
710 Lawrence Expy, Santa Clara, CA 95051
Phone
(408) 851-1000
Enumerated
Nov 3, 2006
Record last updated
Dec 6, 2021 (not updated in 5 years: call before relying on the address or phone)
Medicaid ID
00G793840 CA
Medicare enrollment
Enrolled (PECOS I20101221000404); accepts Medicare assignment
Medical or professional school
University Of California, Davis School Of Medicine, 1992
Entity
Type 1 · individual
Public record from CMS NPPES (open it on the CMS NPI Registry). Enrollment, assignment, school and telehealth: CMS Doctors and Clinicians file, Aug 2026. A record is not a license: verify it with the state board.
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Also registered at 710 Lawrence Expy

A shared address usually means a shared clinic or building; it does not show who employs whom.

  1. Iype Abraham, M.D.Internal Medicine Physician1578737243
  2. Oren Abramson, MDPediatric Gastroenterology Physician1265511307
  3. Jamie Adiarte, PA-CPhysician Assistant1073824413
  4. Sarah Adut, PHDClinical Psychologist1609484831
  5. Najla Ahmadzia, M.D.Student in an Organized Health Care Education/Training Program1568692580
  6. Farhana Ahmed, MDHospitalist Physician1215110002

Verify Ronald Y. Yamaguchi in five checks

  1. 1IdentityNPI record in CMS NPPESNPI lookupConfirmed in NPPES
  2. 2LicenseActive license and public ordersMedical Board of California
    Search for license G79384
    Check the board
  3. 3Other statesLicenses and actions elsewhereDocInfo (FSMB)Not checked
  4. 4ExclusionsMedicare and Medicaid bansHHS-OIG exclusion listNot checked
  5. 5CertificationBoard certificationABMS AOA NCCPA AANPNot checked
Open the California license search

PlainDoctor does not match the HHS-OIG exclusion list to individual records: most entries carry no NPI. Search the OIG exclusion list by name.

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11% fewer Medicare Part D claims than the average urology physician in 2024

1,195 Medicare Part D claims for 420 beneficiaries, against an average of 1,340 among the 10,782 providers of this specialty who prescribed in Part D. Brand-name drugs were 2% of claims. 12 claims were for opioids.

  1. Ronald Yamaguchi1,195
  2. Specialty average1,340

Most prescribed

  1. Finasteride482 claims
  2. Tamsulosin Hcl225 claims
  3. Terazosin Hcl136 claims
  4. Sulfamethoxazole-Trimethoprim55 claims
  5. Ciprofloxacin Hcl44 claims
  6. Trospium Chloride31 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

  1. 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).

Ronald Y. Yamaguchi among 1,524 urology physician records in California

Ronald Y. Yamaguchi, MD is one of 1,524 urology physician records with a practice address in California. 82% 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 8% of them.

  • NPI issued2006 · 8% of these records are older, 51% newer
  • In a Medicare fileYes · 82% of these records are
  • In the CMS Doctors and Clinicians fileYes · 69% of these records are
  • Graduated1992 · median 2003 among the 1,049 with a school on file
  • Record last updated2021 · 59% of these records were not updated in five years or more

Source: CMS NPPES, file of Aug 9, 2026, every record with primary taxonomy 208800000X and a California practice address; Medicare files: CMS Part D Prescribers 2024, MIPS 2023, Open Payments 2024, Doctors and Clinicians (data.cms.gov).

Urology Physician providers in California

There are 1,524 urology physician records in California.

The 8 urology physician records with the nearest ZIP codes

  1. Sarah Chan, MDSanta Clara, CA 950511114186186
  2. Sarah Evans, M.D.Santa Clara, CA 950511114900461
  3. Pauline Filippou, M.D.Santa Clara, CA 950511467849695
  4. David Guo, MDSanta Clara, CA 950511598054991
  5. Robert Harris, MDSanta Clara, CA 950511184703225
  6. Lisa Hata, MDSanta Clara, CA 950511225698566
  7. Mehdi Kamarei, MDSanta Clara, CA 950511528145463
  8. Dale Kunihira, M.D.Santa Clara, CA 950511962522540

Common questions

What is Ronald Y. Yamaguchi, MD's NPI number?

Ronald Y. Yamaguchi, MD's National Provider Identifier (NPI) is 1104905843, issued on Nov 3, 2006. An NPI identifies a provider in billing; it is not a license.

Where is Ronald Y. Yamaguchi, MD located?

The NPPES record lists a practice address at 710 Lawrence Expy, Santa Clara, CA, 95051. Phone: (408) 851-1000. Providers update this record themselves, so call before visiting.

How can I verify Ronald Y. Yamaguchi, MD's license?

NPPES lists California license number G79384, 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 Ronald Y. Yamaguchi, MD prescribe under Medicare Part D?

In 2024, Ronald Y. Yamaguchi, MD had 1,195 Medicare Part D claims for 420 beneficiaries; the average among urology physician prescribers was 1,340. 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.