Willard Quirk, M.D.
Psychiatry Physician · Lancaster, CA
Willard Quirk, M.D. is a psychiatry physician with a practice address in Lancaster, California, and NPI 1821072950, issued on Dec 1, 2005. Check the license (California A109440, as entered in NPPES) on the Medical Board of California; the Medicare figures below come from public CMS files.
- Name
- Willard Quirk
- Credential
- M.D.
- Primary taxonomy
- Psychiatry Physician 2084P0800X
- License numbers
- A109440 CA
ME83506 FL
MD 9499 HI
Self-reported in NPPES; status is on the state search - Practice location
- 506 W Jackman St, Lancaster, CA 93534
- Phone
- (661) 802-1467
- Enumerated
- Dec 1, 2005
- Record last updated
- Oct 13, 2025
- Medicare enrollment
- Enrolled (PECOS I20251219002768); accepts Medicare assignment
- Medical or professional school
- University Of Texas Medical School At Houston, 1994
- Entity
- Type 1 · individual
8 nearest psychiatry physician records → All 8,673 in California → Look up another NPI →
Also registered at 506 W Jackman St
A shared address usually means a shared clinic or building; it does not show who employs whom.
- Sara AbbottDay Training/Habilitation Specialist1760363550
- Angelina AcostaCommunity Health Worker1891403283
- Dana AdoptanteRehabilitation Practitioner1386916997
- Rubi AguilarDay Training/Habilitation Specialist1962280016
- Monique Aguirre RamosDay Training/Habilitation Specialist1013733997
- Lisa AlarconCase Manager/Care Coordinator1457699126
Verify Willard Quirk in five checks
- 1IdentityNPI record in CMS NPPESNPI lookupConfirmed in NPPES
- 2LicenseActive license and public ordersMedical Board of California
Search for license A109440Check the board - 3Other statesLicenses and actions elsewhereDocInfo (FSMB)Not checked
- 4ExclusionsMedicare and Medicaid bansHHS-OIG exclusion listNot checked
- 5CertificationBoard certificationABMS AOA NCCPA AANPNot checked
56% fewer Medicare Part D claims than the average psychiatry physician in 2024
435 Medicare Part D claims for 34 beneficiaries, against an average of 1,000 among the 35,054 providers of this specialty who prescribed in Part D. Brand-name drugs were 17% of claims.
Most prescribed
- Olanzapine43 claims
- Bupropion Hcl Sr39 claims
- Aristada36 claims
- Zolpidem Tartrate35 claims
- Aripiprazole30 claims
- Quetiapine Fumarate30 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.
Willard Quirk among 8,673 psychiatry physician records in California
Willard Quirk, M.D. is one of 8,673 psychiatry physician records with a practice address in California. 67% of them appear in a Medicare file (Part D prescribing, MIPS, Open Payments or Medicare group billing); this one does. Its NPI, issued in 2005, is newer than 0% of them.
- NPI issued2005 · 0% of these records are older, 98% newer
- In a Medicare fileYes · 67% of these records are
- In the CMS Doctors and Clinicians fileYes · 38% of these records are
- Graduated1994 · median 2005 among the 3,295 with a school on file
- Record last updated2025 · 54% of these records were not updated in five years or more
Source: CMS NPPES, file of Aug 9, 2026, every record with primary taxonomy 2084P0800X and a California practice address; Medicare files: CMS Part D Prescribers 2024, MIPS 2023, Open Payments 2024, Doctors and Clinicians (data.cms.gov).
Psychiatry Physician providers in California
There are 8,673 psychiatry physician records in California.
All 8,673 in California → Every provider in Lancaster → Psychiatry Physician nationwide →
The 8 psychiatry physician records with the nearest ZIP codes
- Thomas Carlton, M.D.Lancaster, CA 935341912079518
- Andrea Carter, MDLancaster, CA 935341992091391
- Roy Del-Rosario, M.D.Lancaster, CA 935341740381870
- Omar Anthony Eslao, M.D.Lancaster, CA 935341518112606
- Robert Imani, M.D.Lancaster, CA 935341639374747
- Tiffany Tsai, M.D.Lancaster, CA 935341043483431
- Christy Waters, MDLancaster, CA 935341831249630
- Harald Krueger, M.D.Lancaster, CA 935351477691988
Common questions
What is Willard Quirk, M.D.'s NPI number?
Willard Quirk, M.D.'s National Provider Identifier (NPI) is 1821072950, issued on Dec 1, 2005. An NPI identifies a provider in billing; it is not a license.
Where is Willard Quirk, M.D. located?
The NPPES record lists a practice address at 506 W Jackman St, Lancaster, CA, 93534. Phone: (661) 802-1467. Providers update this record themselves, so call before visiting.
How can I verify Willard Quirk, M.D.'s license?
NPPES lists California license number A109440, 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 Willard Quirk, M.D. prescribe under Medicare Part D?
In 2024, Willard Quirk, M.D. had 435 Medicare Part D claims for 34 beneficiaries; the average among psychiatry physician prescribers was 1,000. 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.