DR. MARY UAN-SIAN FENG M.D.
NPI 1720106693
Radiology - Radiation Oncology in San Francisco, CA
About Dr. Mary Uan-sian Feng M.d. NPPES
Official registry information on file with the National Plan and Provider Enumeration System.
DR. MARY UAN-SIAN FENG M.D. (NPI 1720106693) is an individual radiation oncology provider in San Francisco, California, licensed in California (C143118) and active in the NPI registry since March 2007. She is enrolled in Medicare PECOS, maintains a secondary practice location in Ann Arbor, and is a graduate of Washington University School Of Medicine (2002).
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
Dr. Mary Uan-sian Feng M.d. 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
2Medicare enrollment records show Mary Feng reassigns Medicare billing to 2 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
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 8
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.
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 Mary Feng's NPI number?
The NPI number for Mary Feng is 1720106693. It was assigned to this individual provider in the NPPES registry on March 27, 2007.
Where is Mary Feng located?
Mary Feng practices at 1825 4th Street, L1101, San Francisco, CA 94143. The listed phone number is (415) 502-7222.
What is Mary Feng's specialty?
The primary specialty registered for this NPI is Radiology, specializing in Radiation Oncology, with taxonomy code 2085R0001X.
Is Mary Feng enrolled in Medicare?
Yes. Mary Feng 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 Mary Feng's services?
According to the CMS Revalidation Reassignment List (October 2026 release), Mary Feng reassigns Medicare benefits to 2 organizations: University Of California San Francisco (San Francisco, CA) and Ucsf Medical Group Business Services (San Francisco, 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 Mary Feng'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 Mary Feng was last updated on September 27, 2022. NPI Profile syncs weekly with the NPPES registry data releases published by CMS. This NPI record was last updated 4 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.
# Dr. Mary Uan-Sian Feng, M.D. · NPI 1720106693
Radiation Oncology physician in San Francisco, California. Individual provider, active in the CMS NPPES registry since March 27, 2007.
## Identity
- **NPI:** 1720106693 (Entity type: Individual)
- **Enumerated:** March 27, 2007
- **Primary specialty:** Radiology - Radiation Oncology · taxonomy 2085R0001X
- **State license:** C143118 (California)
- **Sole proprietor:** No
## Practice location
- **Address:** 1825 4TH STREET, L1101, San Francisco, CA 94143
- **Phone:** (415) 502-7222
## 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:** 2 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) · CMS Revalidation Reassignment List, October 2026 release
- **Medical school:** Washington University School Of Medicine, class of 2002
## Record status
- **NPPES last updated:** September 27, 2022
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Source: [NPI Profile](https://npiprofile.com/npi/1720106693) · Data from the CMS NPPES public registry.