William Holliday, MD
NPI 1912402496 · Psychiatry Physician · Torrance, CA
Enrolled with Medicare as Practitioner - Psychiatry · source: CMS PECOS Public Provider Enrollment (2026.04.01)
William Holliday, MD is a Psychiatry Physician provider in Torrance, CA (NPI 1912402496).
Provider details
- NPI number
- 1912402496
- Entity type
- Individual
- Primary specialty
- Psychiatry PhysicianAllopathic & Osteopathic Physicians
- Credential
- MD
- Sex
- Male
- Sole proprietor
- No
- License
- A164022 (CA)
Specialties & taxonomies
Allopathic & Osteopathic Physicians
Other Service Providers
Profile Score
A profile completeness & documented-activity index — NOT a quality, outcomes, or patient-satisfaction rating.
- Registry tenure38% of score
8 yrs in NPPES registry
- Profile completeness38% of score
100% of core fields populated
- Practice footprint23% of score
1 documented practice location
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 · 25 distinct drugs on file.
| Drug | Part D claims (2024) | Beneficiaries |
|---|---|---|
| Trazodone Hcl | 92 | 36 |
| Clonazepam | 84 | 12 |
| Sertraline Hcl | 50 | 22 |
| Fluoxetine Hcl | 45 | 16 |
| Lorazepam | 41 | 14 |
| Bupropion Hclbrand: Bupropion Xl | 39 | 16 |
| Olanzapine | 38 |
Practice location
Mailing address
Registry dates
- Enumerated
- 2018-03-27
- Last updated
- 2022-08-23
- Certified
- 2022-07-26
Frequently asked questions
- What is William Holliday's NPI number?
- William Holliday's National Provider Identifier (NPI) is 1912402496, a unique 10-digit ID issued by CMS for use in standard healthcare transactions.
- What is William Holliday's specialty?
- William Holliday is listed in the NPPES registry with a primary specialty of Psychiatry Physician (Allopathic & Osteopathic Physicians).
- Where is William Holliday located?
- William Holliday's practice location on file with NPPES is 1000 W Carson St, Torrance, CA 90502-2004.
- What is William Holliday's phone number?
- The practice phone number listed in the NPPES registry for William Holliday is (206) 419-2023.
- Does William Holliday accept Medicare?
- William Holliday is approved to bill Medicare according to CMS PECOS enrollment data (2026.04.01). Confirm current participation with the provider before scheduling.
- Is William Holliday's NPI active?
- Yes — William Holliday's NPI (1912402496) is active in the NPPES registry as of the last update on 2022-08-23.
Source: CMS NPPES Data Dissemination (June 2026). NPI Central is not affiliated with CMS. Data is provided as-is from the public registry.