Mark Andrew Willoughby, M.D.
Dermatology Physician · Chula Vista, CA
Mark Andrew Willoughby, M.D. is a dermatology physician with a practice address in Chula Vista, California, and NPI 1215931993, issued on Jun 9, 2005. Check the license (California A69750, as entered in NPPES) on the Medical Board of California; the Medicare figures below come from public CMS files.
- Name
- Mark Andrew Willoughby
- Credential
- M.D.
- Primary taxonomy
- Dermatology Physician 207N00000X
- License number
- A69750 CA
Self-reported in NPPES; status is on the state search - Practice location
- 319 F St, Chula Vista, CA 91910
- Phone
- (619) 476-1200
- Enumerated
- Jun 9, 2005
- Record last updated
- Jul 13, 2026
- Fax
- (619) 420-7849
- Medicaid ID
- 00A697500 CA
- Medicare enrollment
- Enrolled (PECOS I20110222000573); accepts Medicare assignment
- Medical or professional school
- Ohio State University College Of Medicine, 1997
- Entity
- Type 1 · individual
8 nearest dermatology physician records → All 2,083 in California → Look up another NPI →
Also registered at 319 F St
A shared address usually means a shared clinic or building; it does not show who employs whom.
- Erick Mafong, M.D.MOHS-Micrographic Surgery Physician1033113725
- Cole Willoughby, M.D.Dermatopathology Physician1659375301
Verify Mark Andrew Willoughby in five checks
- 1IdentityNPI record in CMS NPPESNPI lookupConfirmed in NPPES
- 2LicenseActive license and public ordersMedical Board of California
Search for license A69750Check the board - 3Other statesLicenses and actions elsewhereDocInfo (FSMB)Not checked
- 4ExclusionsMedicare and Medicaid bansHHS-OIG exclusion listNot checked
- 5CertificationBoard certificationABMS AOA NCCPA AANPNot checked
22% more Medicare Part D claims than the average dermatology physician in 2024
974 Medicare Part D claims for 468 beneficiaries, against an average of 797 among the 12,802 providers of this specialty who prescribed in Part D. Brand-name drugs were 3% of claims.
Most prescribed
- Fluocinonide210 claims
- Hydrocortisone117 claims
- Clobetasol Propionate110 claims
- Triamcinolone Acetonide106 claims
- Ketoconazole64 claims
- Fluorouracil39 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.
The practice group's MIPS final score for 2023 (Medicare payment program): 82.5 of 100
The Merit-based Incentive Payment System score is reported for the practice group, not for one clinician alone. Four categories are weighted into the final score; the average among 454,083 clinicians with a measured score was 83.5.
Source: CMS Quality Payment Program, MIPS performance year 2023, group reporting; category weights for 2023 (qpp.cms.gov).
Industry payments in 2024: $1,226.31
60 payments; by number, the most common kind was food and beverage; the largest payer was Janssen Biotech, Inc. The 10,250 providers of this specialty with any payment received $8,544.61 on average. Payments are reported by manufacturers, not by the provider, and are not a sign of wrongdoing.
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
- Dermatology And Laser Center OF San DiegoChula Vista, CA
Source: CMS Doctors and Clinicians National Downloadable File (the group practices a clinician bills Medicare through) (data.cms.gov).
Mark Andrew Willoughby among 2,083 dermatology physician records in California
Mark Andrew Willoughby, M.D. is one of 2,083 dermatology physician records with a practice address in California. 83% 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, 94% newer
- In a Medicare fileYes · 83% of these records are
- In the CMS Doctors and Clinicians fileYes · 70% of these records are
- Graduated1997 · median 2006 among the 1,450 with a school on file
- Record last updated2026 · 58% of these records were not updated in five years or more
Source: CMS NPPES, file of Aug 9, 2026, every record with primary taxonomy 207N00000X and a California practice address; Medicare files: CMS Part D Prescribers 2024, MIPS 2023, Open Payments 2024, Doctors and Clinicians (data.cms.gov).
Dermatology Physician providers in California
There are 2,083 dermatology physician records in California.
All 2,083 in California → Every provider in Chula Vista → Dermatology Physician nationwide →
The 8 dermatology physician records with the nearest ZIP codes
- Amy Han, MDChula Vista, CA 919101710945365
- Jacqueline McKeseyChula Vista, CA 919101811422801
- Jennifer Rullan, MDChula Vista, CA 919101447484811
- Alexander Stein, MDChula Vista, CA 919101760431654
- Hanny Chan, MDChula Vista, CA 919131669520524
- Amir Djavid, MDChula Vista, CA 919131023758091
- Nancy Maly, M.D.Chula Vista, CA 919131073874178
- Maria Parente, M.D.Chula Vista, CA 919131740293778
Common questions
What is Mark Andrew Willoughby, M.D.'s NPI number?
Mark Andrew Willoughby, M.D.'s National Provider Identifier (NPI) is 1215931993, issued on Jun 9, 2005. An NPI identifies a provider in billing; it is not a license.
Where is Mark Andrew Willoughby, M.D. located?
The NPPES record lists a practice address at 319 F St, Chula Vista, CA, 91910. Phone: (619) 476-1200. Providers update this record themselves, so call before visiting.
How can I verify Mark Andrew Willoughby, M.D.'s license?
NPPES lists California license number A69750, 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 Mark Andrew Willoughby, M.D. prescribe under Medicare Part D?
In 2024, Mark Andrew Willoughby, M.D. had 974 Medicare Part D claims for 468 beneficiaries; the average among dermatology physician prescribers was 797. Part D covers Medicare prescriptions only.
What is Mark Andrew Willoughby, M.D.'s MIPS final score?
The 2023 MIPS final score is 82.5 of 100, reported for the practice group. The average among 454,083 clinicians with a measured score was 83.5.
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.