NPPES file of Aug 9, 2026

Warren Toshiro Yamashita, MD, MPH

Addiction Medicine (Family Medicine) Physician · Tustin, CA

Warren Toshiro Yamashita, MD, MPH is an addiction medicine (family medicine) physician with a practice address in Tustin, California, and NPI 1982137691, issued on Apr 10, 2017. Check the license (California A167101, 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
1982137691
Name
Warren Toshiro Yamashita
Credential
MD, MPH
Primary taxonomy
Addiction Medicine (Family Medicine) Physician 207QA0401X
License number
A167101 CA
Self-reported in NPPES; status is on the state search
Practice location
1 Hope Dr, Tustin, CA 92782
Phone
(714) 247-0300
Enumerated
Apr 10, 2017
Record last updated
May 5, 2022
Fax
(714) 259-1598
Medicare enrollment
Enrolled (PECOS I20201015002454); accepts Medicare assignment
Medical or professional school
University Of Southern California Keck School Of Medicine, 2017
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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8 nearest addiction medicine (family medicine) physician records → All 124 in California → Look up another NPI →

Also registered at 1 Hope Dr

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

  1. Lisa Abdishoo, MDInternal Medicine Physician1881776326
  2. Christine Akparanta, MDFamily Medicine Physician1184129884
  3. Karina ArredondoClinical Social Worker1114474897
  4. Robert Bader, MDInternal Medicine Physician1225111610
  5. Eun Beenen, ACSWClinical Social Worker1811696347
  6. Christopher BetancurCase Manager/Care Coordinator1629845466

Verify Warren Toshiro Yamashita in five checks

  1. 1IdentityNPI record in CMS NPPESNPI lookupConfirmed in NPPES
  2. 2LicenseActive license and public ordersMedical Board of California
    Search for license A167101    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

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67% fewer Medicare Part D claims than the average addiction medicine (family medicine) physician in 2024

217 Medicare Part D claims for 48 beneficiaries, against an average of 664 among the 581 providers of this specialty who prescribed in Part D.

  1. Warren Yamashita217
  2. Specialty average664

Most prescribed

  1. Atorvastatin Calcium16 claims
  2. Diazepam14 claims
  3. Lisinopril12 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: $464.65

18 payments; by number, the most common kind was food and beverage; the largest payer was Abbvie Inc. The 305 providers of this specialty with any payment received $1,151.00 on average. Payments are reported by manufacturers, not by the provider, and are not a sign of wrongdoing.

  1. Warren Yamashita$464.65
  2. Specialty average$1,151.00

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

  1. Harbor Community Clinic IncSan Pedro, CA

Source: CMS Doctors and Clinicians National Downloadable File (the group practices a clinician bills Medicare through) (data.cms.gov).

Warren Toshiro Yamashita among 124 addiction medicine (family medicine) physician records in California

Warren Toshiro Yamashita, MD, MPH is one of 124 addiction medicine (family medicine) physician records with a practice address in California. 78% of them appear in a Medicare file (Part D prescribing, MIPS, Open Payments or Medicare group billing); this one does. Its NPI, issued in 2017, is newer than 62% of them.

  • NPI issued2017 · 62% of these records are older, 31% newer
  • In a Medicare fileYes · 78% of these records are
  • In the CMS Doctors and Clinicians fileYes · 52% of these records are
  • Graduated2017 · median 2015 among the 64 with a school on file
  • Record last updated2022 · 33% of these records were not updated in five years or more

Source: CMS NPPES, file of Aug 9, 2026, every record with primary taxonomy 207QA0401X and a California practice address; Medicare files: CMS Part D Prescribers 2024, MIPS 2023, Open Payments 2024, Doctors and Clinicians (data.cms.gov).

Addiction Medicine (Family Medicine) Physician providers in California

There are 124 addiction medicine (family medicine) physician records in California.

All 124 in California → Every provider in Tustin → Addiction Medicine (Family Medicine) Physician nationwide →

The 8 addiction medicine (family medicine) physician records with the nearest ZIP codes

  1. Michael Stone, M DSanta Ana, CA 927051730221698
  2. Jonathan Watson, MDSanta Ana, CA 927031992151765
  3. Daniel Headrick, M.D.San Juan Capistrano, CA 926751770649816
  4. Atul Grover, MDNewport Beach, CA 926631639166523
  5. Steven Ey, M.D.Newport Beach, CA 926581821013285
  6. Kenneth Gheysar, M.D.Laguna Hills, CA 926531609992171
  7. Stephen Groth, MDLaguna Beach, CA 926511982762761
  8. Anthony Ocana, MD, CCFP, FASAMLaguna Beach, CA 926511093363848

Common questions

What is Warren Toshiro Yamashita, MD, MPH's NPI number?

Warren Toshiro Yamashita, MD, MPH's National Provider Identifier (NPI) is 1982137691, issued on Apr 10, 2017. An NPI identifies a provider in billing; it is not a license.

Where is Warren Toshiro Yamashita, MD, MPH located?

The NPPES record lists a practice address at 1 Hope Dr, Tustin, CA, 92782. Phone: (714) 247-0300. Providers update this record themselves, so call before visiting.

How can I verify Warren Toshiro Yamashita, MD, MPH's license?

NPPES lists California license number A167101, 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 Warren Toshiro Yamashita, MD, MPH prescribe under Medicare Part D?

In 2024, Warren Toshiro Yamashita, MD, MPH had 217 Medicare Part D claims for 48 beneficiaries; the average among addiction medicine (family medicine) physician prescribers was 664. 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.

Written with AI tools from the named public files; every figure is computed from those files (how it is made).

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.