MARGARET RIORDAN MD
NPI 1902061955
Neurological Surgery in San Francisco, CA
About Margaret Riordan Md NPPES
Official registry information on file with the National Plan and Provider Enumeration System.
MARGARET RIORDAN MD (NPI 1902061955) is an individual neurological surgery provider in San Francisco, California, licensed in California (137141) and active in the NPI registry since July 2008. She is enrolled in Medicare PECOS, maintains a secondary practice location in Wilkes-barre, and is a graduate of University Of Iowa, Rj & L Carver College Of Medicine (2008).
NPPES Registry Identity
Specialties & Licenses
Secondary Practice Location 1
Medicare Participation & PECOS CMS
Medicare enrollment, assignment, billing reassignment, and ordering and referring status from CMS.
Medicare Enrollment Status
Enrolled in Medicare and accepts Medicare assignment
Margaret Riordan Md is registered in PECOS and agrees to accept the Medicare-approved amount as full payment. Medicare patients are not billed beyond the standard deductible and coinsurance.
Medicare Billing Reassignments
4Medicare enrollment records show Margaret Riordan reassigns Medicare billing to 4 organizations. Each organization bills Medicare for the services this provider delivers there; the nearest is listed first.
San Francisco, CA 94143
- Reassigned Medicare billing, California enrollment
- 5,645 clinicians in this Medicare group
San Francisco, CA 94122
- Reassigned Medicare billing, California enrollment
- 5,544 clinicians in this Medicare group
Alameda, CA 94501
- Reassigned Medicare billing, California enrollment
- 900 clinicians in this Medicare group
Palo Alto, CA 94306
- Reassigned Medicare billing, California enrollment
- 2,460 clinicians in this Medicare group
Source: CMS Revalidation Reassignment List, October 2026 release. Reassignment records can lag staffing changes; confirm a current affiliation with the organization.
Areas of Expertise CMS Part B claims
Services this provider delivered to Medicare fee-for-service patients, from the CMS Medicare utilization data. Higher counts generally reflect more experience with a service; care delivered outside Medicare is not included.
Physician Visit Costs CMS claims · ZIP area
Typical Medicare office-visit costs in the 94143 ZIP code area, from fee-for-service claims. These are area statistics, not this provider’s prices; actual charges vary by service and coverage.
Medicare Quality Performance CMS QPP · MIPS
Performance in the CMS Quality Payment Program: the MIPS final score across four weighted categories, and the individual quality measures reported to Medicare.
Other Providers at the Same Location NPPES 20
Providers registered at the same practice address, or within the immediate area, according to the NPPES registry.
SAN FRANCISCO, CA 94143
SAN FRANCISCO, CA 94143
SAN FRANCISCO, CA 94143
SAN FRANCISCO, CA 94143
Frequently 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 Riordan's NPI number?
The NPI number for Margaret Riordan is 1902061955. It was assigned to this individual provider in the NPPES registry on July 18, 2008.
Where is Margaret Riordan located?
Margaret Riordan practices at 400 Parnassus Ave, San Francisco, CA 94143. The listed phone number is (415) 472-1000.
What is Margaret Riordan's specialty?
The primary specialty registered for this NPI is Neurological Surgery with taxonomy code 207T00000X.
Is Margaret Riordan enrolled in Medicare?
Yes. Margaret Riordan is registered in the Medicare PECOS system and accepts Medicare assignment, which means accepting the Medicare-approved amount as payment in full for covered services.
Which organizations bill Medicare for Margaret Riordan's services?
According to the CMS Revalidation Reassignment List (October 2026 release), Margaret Riordan reassigns Medicare benefits to 4 organizations: University Of California San Francisco (San Francisco, CA), Ucsf Medical Group Business Services (San Francisco, CA), Alameda Health System (Alameda, CA) and County Of Santa Clara (Palo Alto, CA). Each 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 Margaret Riordan's services. Reassignment records can lag staffing changes; confirm current arrangements with the organization.
When was this NPI record last updated?
The NPPES record for Margaret Riordan was last updated on March 17, 2018. NPI Profile syncs weekly with the NPPES registry data releases published by CMS. This NPI record was last updated 8 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 Riordan, MD · NPI 1902061955
Neurological Surgery physician in San Francisco, California. Individual provider, active in the CMS NPPES registry since July 18, 2008.
## Identity
- **NPI:** 1902061955 (Entity type: Individual)
- **Enumerated:** July 18, 2008
- **Primary specialty:** Neurological Surgery · taxonomy 207T00000X
- **State license:** 137141 (California)
- **Sole proprietor:** No
## Practice location
- **Address:** 400 PARNASSUS AVE, San Francisco, CA 94143-2202
- **Phone:** (415) 472-1000
## Medicare
- **Medicare:** Enrolled (PECOS); accepts Medicare assignment
- **Ordering & referring:** eligible for Part B labs & imaging, durable medical equipment, home health, power mobility devices
- **Bills Medicare through:** 4 organizations under Medicare reassignment (form CMS-855R): University Of California San Francisco (NPI 1346329380, San Francisco, CA); Ucsf Medical Group Business Services (NPI 1477624104, San Francisco, CA); Alameda Health System (NPI 1124446158, Alameda, CA); County Of Santa Clara (NPI 1144330614, Palo Alto, CA) · CMS Revalidation Reassignment List, October 2026 release
- **Medical school:** University Of Iowa, Rj & L Carver College Of Medicine, class of 2008
## Record status
- **NPPES last updated:** March 17, 2018
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Source: [NPI Profile](https://npiprofile.com/npi/1902061955) · Data from the CMS NPPES public registry.