Willard Quirk, M.D.
NPI 1821072950 · Psychiatry Physician · Lancaster, CA
Willard Quirk, M.D. is a Psychiatry Physician provider in Lancaster, CA (NPI 1821072950).
Provider details
- NPI number
- 1821072950
- Entity type
- Individual
- Primary specialty
- Psychiatry PhysicianAllopathic & Osteopathic Physicians
- Credential
- M.D.
- Sex
- Male
- Sole proprietor
- Yes
- License
- MD 9499 (HI)
Specialties & taxonomies
Allopathic & Osteopathic Physicians
Allopathic & Osteopathic Physicians
Allopathic & Osteopathic Physicians
Profile Score
A profile completeness & documented-activity index — NOT a quality, outcomes, or patient-satisfaction rating.
- Registry tenure38% of score
20 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 · 11 distinct drugs on file.
| Drug | Part D claims (2024) |
|---|---|
| Olanzapine | 43 |
| Bupropion Hclbrand: Bupropion Hcl Sr | 39 |
| Aripiprazole Lauroxilbrand: Aristada | 36 |
| Zolpidem Tartrate | 35 |
| Aripiprazole | 30 |
| Quetiapine Fumarate | 30 |
| Lithium Carbonate | 23 |
| Amitriptyline Hcl | 19 |
| Trazodone Hcl | 15 |
Practice location
Mailing address
Registry dates
- Enumerated
- 2005-12-01
- Last updated
- 2025-10-13
- Certified
- 2025-10-13
Frequently asked questions
- What is Willard Quirk's NPI number?
- Willard Quirk's National Provider Identifier (NPI) is 1821072950, a unique 10-digit ID issued by CMS for use in standard healthcare transactions.
- What is Willard Quirk's specialty?
- Willard Quirk is listed in the NPPES registry with a primary specialty of Psychiatry Physician (Allopathic & Osteopathic Physicians).
- Where is Willard Quirk located?
- Willard Quirk's practice location on file with NPPES is 506 W Jackman St, Lancaster, CA 93534-2531.
- What is Willard Quirk's phone number?
- The practice phone number listed in the NPPES registry for Willard Quirk is (661) 802-1467.
- Is Willard Quirk's NPI active?
- Yes — Willard Quirk's NPI (1821072950) is active in the NPPES registry as of the last update on 2025-10-13.
Source: CMS NPPES Data Dissemination (June 2026). NPI Central is not affiliated with CMS. Data is provided as-is from the public registry.