Warren Yamashita, MD, MPH
NPI 1982137691 · Addiction Medicine (Family Medicine) Physician · Tustin, CA
Enrolled with Medicare as Practitioner - Family Practice · source: CMS PECOS Public Provider Enrollment (2026.04.01)
Warren Yamashita, MD, MPH is a Addiction Medicine (Family Medicine) Physician provider in Tustin, CA (NPI 1982137691).
Provider details
- NPI number
- 1982137691
- Entity type
- Individual
- Primary specialty
- Addiction Medicine (Family Medicine) PhysicianAllopathic & Osteopathic Physicians
- Credential
- MD, MPH
- Sex
- Male
- Sole proprietor
- No
- License
- A167101 (CA)
Specialties & taxonomies
Allopathic & Osteopathic Physicians
Profile Score
A profile completeness & documented-activity index — NOT a quality, outcomes, or patient-satisfaction rating.
- Registry tenure33% of score
9 yrs in NPPES registry
- Profile completeness33% of score
100% of core fields populated
- Practice footprint20% of score
4 documented practice locations
- Open Payments transparency13% of score
Has Open Payments disclosures (2024)
Signals a provider has no public data for (e.g. Medicare claims) are left out of the score entirely — never counted as zero — so providers without that data are not penalized. See the full formula and weights in our methodology.
What this provider prescribes (Medicare Part D)
Top drugs by Medicare Part D claim volume, 2024 · 3 distinct drugs on file.
| Drug | Part D claims (2024) |
|---|---|
| Atorvastatin Calcium | 16 |
| Diazepam | 14 |
| Lisinopril | 12 |
Medicare Part D only. These counts cover prescriptions paid through Medicare Part D in 2024 — they do notinclude cash-pay, commercial-insurance, Medicaid, or Part B–administered drugs, and badly undercount high cash-pay categories (e.g. GLP-1 weight-loss, testosterone, and ED medications). Any drug with 10 or fewer claims is omitted by CMS, and beneficiary counts under 11 are suppressed — so a missing drug means no Part D record, never zero. This is a factual claims summary, not an endorsement, not medical advice, and not a consumer report. Source: CMS Medicare Part D Prescribers — by Provider and Drug.
Transparency — industry payments
Based on CMS Open Payments, 2024; not all care is captured.
$465 across 18 records (Open Payments 2024)
Open Payments discloses payments and transfers of value (meals, travel, consulting, research, royalties) from drug and device makers to providers. This is a transparency signal, not a verdict — such payments are legal and common, and their presence is neither an endorsement nor a criticism. Source: CMS Open Payments, program year 2024.
Practice location
Mailing address
Additional practice locations (3)
- 947 S Anaheim Blvd Ste 260Anaheim, CA 92805-5591Phone: (714) 247-0300Fax: (714) 259-1598
- 1100b N Tustin Ave Ste aSanta Ana, CA 92705-3505Phone: (714) 247-0300Fax: (714) 259-1598
- 14642 Newport Ave Ste 200Tustin, CA 92780-6058Phone: (714) 247-0300Fax: (714) 259-1598
Registry dates
- Enumerated
- 2017-04-10
- Last updated
- 2022-05-05
- Certified
- 2022-05-05
Frequently asked questions
- What is Warren Yamashita's NPI number?
- Warren Yamashita's National Provider Identifier (NPI) is 1982137691, a unique 10-digit ID issued by CMS for use in standard healthcare transactions.
- What is Warren Yamashita's specialty?
- Warren Yamashita is listed in the NPPES registry with a primary specialty of Addiction Medicine (Family Medicine) Physician (Allopathic & Osteopathic Physicians).
- Where is Warren Yamashita located?
- Warren Yamashita's practice location on file with NPPES is 1 Hope Dr, Tustin, CA 92782-0221.
- What is Warren Yamashita's phone number?
- The practice phone number listed in the NPPES registry for Warren Yamashita is (714) 247-0300.
- Does Warren Yamashita accept Medicare?
- Warren Yamashita is approved to bill Medicare according to CMS PECOS enrollment data (2026.04.01). Confirm current participation with the provider before scheduling.
- Is Warren Yamashita's NPI active?
- Yes — Warren Yamashita's NPI (1982137691) is active in the NPPES registry as of the last update on 2022-05-05.
Source: CMS NPPES Data Dissemination (June 2026). NPI Central is not affiliated with CMS. Data is provided as-is from the public registry.