Margaret Shannon, M.D.
Margaret Shannon, M.D. is a Dermatology Physician in Costa Mesa, CA, registered under NPI 1265449441. NPPES records them as a sole proprietor, meaning the practice is not incorporated as a separate legal entity.
Getting there
The practice address on file is 275 VICTORIA ST SUITE 1H, Costa Mesa, CA 92627. We have not yet mapped what surrounds this office — parking, transit, and nearby pharmacies are added as our data collection reaches each location.
Credentials and Medicare
| Licence | State | Specialty |
|---|---|---|
| G42251 | CA | Dermatology Physician primary |
This provider holds licence G42251 issued in CA. A licence number in NPPES reflects what was filed at registration — it does not confirm the licence is still active today.
- Status
- Approved
- Provider type
- Practitioner - Dermatology
- PAC ID
- 2264626191
Medicare enrolment is recorded as approved under the provider type Practitioner - Dermatology. This means the provider is enrolled to bill Medicare, though it does not tell you whether they are currently accepting new Medicare patients. Call the office to confirm.
What Dermatology covers
A dermatologist is trained to diagnose and treat pediatric and adult patients with benign and malignant disorders of the skin, mouth, external genitalia, hair and nails, as well as a number of sexually transmitted diseases. The dermatologist has had additional training and experience in the diagnosis and treatment of skin cancers, melanomas, moles and other tumors of the skin, the management of contact dermatitis and other allergic and nonallergic skin disorders, and in the recognition of the skin manifestations of systemic (including internal malignancy) and infectious diseases. Dermatologists have special training in dermatopathology and in the surgical techniques used in dermatology. They also have expertise in the management of cosmetic disorders of the skin such as hair loss and scars and the skin changes associated with aging. NUCC Health Care Provider Taxonomy, code 207N00000X
The taxonomy records how the provider classifies their own practice. It does not confirm which conditions they currently treat, whether they are accepting new patients, or which insurance they take — call the office for that.
Full NPPES record
An NPI-1 identifies a single person. It stays with the clinician for life, even if they move practice or change state, which is why the address on file can lag behind where they actually work today.
| NPI | 1265449441 valid check digit |
|---|---|
| Entity type | Individual (NPI-1) |
| Enumeration date | Aug 1, 2006 |
| Last updated | Aug 5, 2010 |
| Status | Active |
| Sole proprietor | Yes |
| Credential | M.D. |
| Practice address |
275 VICTORIA ST SUITE 1H Costa Mesa, CA 92627 (949) 646-2311 Fax (949) 646-1064 |
Number check
How the check works, step by step
Every NPI carries a Luhn check digit — the same scheme used on credit cards. CMS prefixes the number with 80840 before computing it, which marks it as a US health identifier.
| Digit | 8 | 0 | 8 | 4 | 0 | 1 | 2 | 6 | 5 | 4 | 4 | 9 | 4 | 4 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Doubled? | — | ×2 | — | ×2 | — | ×2 | — | ×2 | — | ×2 | — | ×2 | — | ×2 |
| Value | 8 | 0 | 8 | 8 | 0 | 2 | 2 | 3 | 5 | 8 | 4 | 9 | 4 | 8 |
Sum = 69 · next multiple of 10 = 70 · check digit = 1 · actual last digit = 1
A valid check digit only means the number is well-formed. It does not mean the provider is licensed, active, or in good standing — those are separate questions answered by the sections above.