MARGARET M SHANNON, MD, INC
NPI 1326358052
Dermatology in Costa Mesa, CA
About Margaret M Shannon, Md, Inc NPPES
Official registry information on file with the National Plan and Provider Enumeration System.
MARGARET M SHANNON, MD, INC (NPI 1326358052) is a healthcare organization registered as a dermatology in Costa Mesa, California and active in the NPI registry since October 2010. The organization holds a CLIA Certificate of Compliance certificate valid through August 31, 2027 and lists Margaret M Shannon, Owner, as its authorized official.
NPPES Registry Identity
Specialties & Licenses
Other Identifiers 1
Group Practice 1
Medicare Participation & PECOS CMS
Medicare enrollment and the clinicians who bill Medicare through this organization, from CMS.
Medicare Enrollment Status
Enrolled in Medicare (PECOS)
Margaret M Shannon, Md, Inc is registered in the CMS Provider Enrollment, Chain and Ownership System (PECOS).
Clinicians Billing Medicare Through This Organization
Medicare enrollment records show 1 clinician reassigns Medicare billing to Margaret M Shannon, MD, Inc, which bills Medicare for the services this clinician delivers.
Clinician (1)
Source: CMS Revalidation Reassignment List, October 2026 release. Reassignment records can lag staffing changes; confirm a current affiliation with the organization.
CLIA Laboratory Certificates CMS CLIA
Laboratory certificates issued under the Clinical Laboratory Improvement Amendments (CLIA) program, which sets federal quality standards for human laboratory testing in the United States. There is no official CMS crosswalk between CLIA and NPI numbers; these certificates are associated with this NPI by matching facility names, locations and phone numbers in the CMS CLIA registry.
Certificate of Compliance 05D0687205
Margaret Shannon MD, Inc · Newport Beach, CAFrequently Asked Questions NPPES & CMS
Common questions about this NPI record, answered from the official NPPES registry and CMS datasets shown on this page.
What is Margaret M Shannon, MD, Inc's NPI number?
The NPI number for Margaret M Shannon, MD, Inc is 1326358052. It was assigned to this organization in the NPPES registry on October 15, 2010.
Where is Margaret M Shannon, MD, Inc located?
Margaret M Shannon, MD, Inc is located at 275 Victoria St Ste 1H, Costa Mesa, CA 92627. The listed phone number is (949) 646-2311.
What is Margaret M Shannon, MD, Inc's specialty?
The primary specialty registered for this NPI is Dermatology with taxonomy code 207N00000X.
Is Margaret M Shannon, MD, Inc enrolled in Medicare?
Yes. Margaret M Shannon, MD, Inc is registered in the Medicare PECOS enrollment system.
How many clinicians bill Medicare through Margaret M Shannon, MD, Inc?
According to the CMS Revalidation Reassignment List (October 2026 release), 1 clinician (Dermatology) reassigns their Medicare billing to Margaret M Shannon, MD, Inc. A reassignment is filed with Medicare on form CMS-855R, signed by both the clinician and the organization, and lets the organization bill Medicare and receive payment for the clinician's services. Reassignment records can lag staffing changes; confirm a current affiliation with the organization.
Does Margaret M Shannon, MD, Inc hold a CLIA laboratory certificate?
Yes. A Certificate of Compliance (number 05D0687205) is associated with this NPI, valid through August 31, 2027. CLIA certificates authorize laboratory testing under the federal Clinical Laboratory Improvement Amendments program.
When was this NPI record last updated?
The NPPES record for Margaret M Shannon, MD, Inc was last updated on November 2, 2010. NPI Profile syncs weekly with the NPPES registry data releases published by CMS. This NPI record was last updated 15 years ago. If this record has changed at CMS more recently, you can request an on-demand re-check against the live CMS registry, directly from this page.
# Margaret M Shannon, Md, Inc · NPI 1326358052
Dermatology organization in Costa Mesa, California. Organization record, active in the CMS NPPES registry since October 15, 2010.
## Identity
- **NPI:** 1326358052 (Entity type: Organization)
- **Enumerated:** October 15, 2010
- **Primary specialty:** Dermatology · taxonomy 207N00000X
- **Organization subpart:** No
- **Authorized official:** Margaret Shannon, OWNER
## Practice location
- **Address:** 275 VICTORIA ST STE 1H, Costa Mesa, CA 92627-1906
- **Phone:** (949) 646-2311 · **Fax:** (949) 646-1064
## Medicare
- **Medicare:** Enrolled in Medicare (PECOS)
- **Clinicians billing through this organization:** 1 clinician (Dermatology) reassigns Medicare billing to this organization (form CMS-855R) · CMS Revalidation Reassignment List, October 2026 release
## Record status
- **NPPES last updated:** November 2, 2010
- **Other identifiers:** Medicare UPIN A48881 (CA)
- **CLIA laboratory certificates:** 1 on file
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Source: [NPI Profile](https://npiprofile.com/npi/1326358052) · Data from the CMS NPPES public registry.