Margaret M. Shannon, M.D.
Dermatology Physician · Costa Mesa, CA
Margaret M. Shannon, M.D. is a dermatology physician with a practice address in Costa Mesa, California, and NPI 1265449441, issued on Aug 1, 2006. Check the license (California G42251, as entered in NPPES) on the Medical Board of California; the Medicare figures below come from public CMS files.
- Name
- Margaret M. Shannon
- Credential
- M.D.
- Primary taxonomy
- Dermatology Physician 207N00000X
- License number
- G42251 CA
Self-reported in NPPES; status is on the state search - Practice location
- 275 Victoria St, Costa Mesa, CA 92627
- Phone
- (949) 646-2311
- Enumerated
- Aug 1, 2006
- Record last updated
- Aug 5, 2010 (not updated in 16 years: call before relying on the address or phone)
- Fax
- (949) 646-1064
- Medicare enrollment
- Enrolled (PECOS I20101104000305); accepts Medicare assignment
- Medical or professional school
- Georgetown University School Of Medicine, 1979
- Entity
- Type 1 · individual
8 nearest dermatology physician records → All 2,083 in California → Look up another NPI →
Also registered at 275 Victoria St
A shared address usually means a shared clinic or building; it does not show who employs whom.
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Verify Margaret M. Shannon in five checks
- 1IdentityNPI record in CMS NPPESNPI lookupConfirmed in NPPES
- 2LicenseActive license and public ordersMedical Board of California
Search for license G42251Check the board - 3Other statesLicenses and actions elsewhereDocInfo (FSMB)Not checked
- 4ExclusionsMedicare and Medicaid bansHHS-OIG exclusion listNot checked
- 5CertificationBoard certificationABMS AOA NCCPA AANPNot checked
32% fewer Medicare Part D claims than the average dermatology physician in 2024
544 Medicare Part D claims for 243 beneficiaries, against an average of 797 among the 12,802 providers of this specialty who prescribed in Part D. Brand-name drugs were 4% of claims.
Most prescribed
- Mupirocin89 claims
- Triamcinolone Acetonide81 claims
- Hydrocortisone42 claims
- Clobetasol Propionate38 claims
- Cephalexin37 claims
- Valacyclovir32 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 MIPS final score for 2023 (Medicare payment program): 0 of 100
The Merit-based Incentive Payment System score is reported for this clinician. 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; category weights for 2023 (qpp.cms.gov).
Industry payments in 2024: $284.02
12 payments; by number, the most common kind was food and beverage; the largest payer was Regeneron Healthcare Solutions, 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.
Margaret M. Shannon among 2,083 dermatology physician records in California
Margaret M. Shannon, 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 2006, is newer than 6% of them.
- NPI issued2006 · 6% of these records are older, 56% newer
- In a Medicare fileYes · 83% of these records are
- In the CMS Doctors and Clinicians fileYes · 70% of these records are
- Graduated1979 · median 2006 among the 1,450 with a school on file
- Record last updated2010 · 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 Costa Mesa → Dermatology Physician nationwide →
The 8 dermatology physician records with the nearest ZIP codes
- Daniel Dwyer, M.D.Costa Mesa, CA 926271992889232
- Rita Nijjar, PA-CCosta Mesa, CA 926271245306935
- Raymond Kleinfelder, D.O.Costa Mesa, CA 926261659751121
- Bernice YanCosta Mesa, CA 926261891255238
- Catherine Lee, M.D.Corona Del Mar, CA 926251992821797
- Maryam Moinfar, MDDana Point, CA 926291376515403
- Mark Tran, M.D.Corona Del Mar, CA 926251205098696
- Ira Bell, M.D.Lake Forest, CA 926301336114545
Common questions
What is Margaret M. Shannon, M.D.'s NPI number?
Margaret M. Shannon, M.D.'s National Provider Identifier (NPI) is 1265449441, issued on Aug 1, 2006. An NPI identifies a provider in billing; it is not a license.
Where is Margaret M. Shannon, M.D. located?
The NPPES record lists a practice address at 275 Victoria St, Costa Mesa, CA, 92627. Phone: (949) 646-2311. Providers update this record themselves, so call before visiting.
How can I verify Margaret M. Shannon, M.D.'s license?
NPPES lists California license number G42251, 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 Margaret M. Shannon, M.D. prescribe under Medicare Part D?
In 2024, Margaret M. Shannon, M.D. had 544 Medicare Part D claims for 243 beneficiaries; the average among dermatology physician prescribers was 797. Part D covers Medicare prescriptions only.
What is Margaret M. Shannon, M.D.'s MIPS final score?
The 2023 MIPS final score is 0 of 100. 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.