RYAN D. MCMAHAN MD, MAS
NPI 1356978308
Internal Medicine in San Francisco, CA
About Ryan D. Mcmahan Md, Mas NPPES
Official registry information on file with the National Plan and Provider Enumeration System.
RYAN D. MCMAHAN MD, MAS (NPI 1356978308) is an individual internal medicine provider in San Francisco, California, licensed in California (A185859) and active in the NPI registry since March 2020. He is enrolled in Medicare PECOS, maintains a secondary practice location in San Francisco, and is a graduate of Other (2020).
NPPES Registry Identity
Specialties & Licenses 2
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
Ryan D. Mcmahan Md, Mas 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
6Medicare enrollment records show Ryan Mcmahan reassigns Medicare billing to 6 organizations. Each organization bills Medicare for the services this provider delivers there; the nearest is listed first.
San Francisco, CA 94116
- Reassigned Medicare billing, California enrollment
- 20,078 clinicians in this Medicare group
San Francisco, CA 94143
- Reassigned Medicare billing, California enrollment
- 2,112 clinicians in this Medicare group
San Francisco, CA 94115
- Reassigned Medicare billing, California enrollment
- 1,573 clinicians in this Medicare group
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
San Francisco, CA 94110
- Reassigned Medicare billing, California enrollment
- 637 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.
Physician Visit Costs CMS claims · ZIP area
Typical Medicare office-visit costs in the 94115 ZIP code area, from fee-for-service claims. These are area statistics, not this provider’s prices; actual charges vary by service and coverage.
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 94115
SAN FRANCISCO, CA 94115
SAN FRANCISCO, CA 94115
SAN FRANCISCO, CA 94115
SAN FRANCISCO, CA 94115
SAN FRANCISCO, CA 94115
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 Ryan Mcmahan's NPI number?
The NPI number for Ryan Mcmahan is 1356978308. It was assigned to this individual provider in the NPPES registry on March 26, 2020.
Where is Ryan Mcmahan located?
Ryan Mcmahan practices at 2425 Geary Blvd, San Francisco, CA 94115. The listed phone number is (415) 833-2000.
What is Ryan Mcmahan's specialty?
The primary specialty registered for this NPI is Internal Medicine with taxonomy code 207R00000X.
Is Ryan Mcmahan enrolled in Medicare?
Yes. Ryan Mcmahan 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 Ryan Mcmahan's services?
According to the CMS Revalidation Reassignment List (October 2026 release), Ryan Mcmahan reassigns Medicare benefits to 6 organizations: Permanente Medical Group Inc (San Francisco, CA), Regents Of The University Of California (San Francisco, CA), City & County Of San Francisco (San Francisco, CA), University Of California San Francisco (San Francisco, CA), Ucsf Medical Group Business Services (San Francisco, CA) and 1 more organization, listed in the Medicare section above. 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 Ryan Mcmahan'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 Ryan Mcmahan was last updated on October 6, 2025. NPI Profile syncs weekly with the NPPES registry data releases published by CMS. This NPI record was last updated 13 months 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.
# Ryan D. Mcmahan, MD, MAS · NPI 1356978308
Internal Medicine physician in San Francisco, California. Individual provider, active in the CMS NPPES registry since March 26, 2020.
## Identity
- **NPI:** 1356978308 (Entity type: Individual)
- **Enumerated:** March 26, 2020
- **Primary specialty:** Internal Medicine · taxonomy 207R00000X
- **State license:** A185859 (California)
- **Sole proprietor:** Yes
## Practice location
- **Address:** 2425 GEARY BLVD, San Francisco, CA 94115-3358
- **Phone:** (415) 833-2000
## 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:** 6 organizations under Medicare reassignment (form CMS-855R): Permanente Medical Group Inc (NPI 1841373800, San Francisco, CA); Regents Of The University Of California (NPI 1235322348, San Francisco, CA); City & County Of San Francisco (NPI 1932140795, San Francisco, CA); University Of California San Francisco (NPI 1346329380, San Francisco, CA); Ucsf Medical Group Business Services (NPI 1477624104, San Francisco, CA); and 1 more · CMS Revalidation Reassignment List, October 2026 release
- **Medical school:** Other, class of 2020
## Record status
- **NPPES last updated:** October 6, 2025
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Source: [NPI Profile](https://npiprofile.com/npi/1356978308) · Data from the CMS NPPES public registry.