DR. MARY P MERCER M.D.
NPI 1104014265
Emergency Medicine in Stanford, CA
About Dr. Mary P Mercer M.d. NPPES
Official registry information on file with the National Plan and Provider Enumeration System.
DR. MARY P MERCER M.D. (NPI 1104014265) is an individual emergency medicine provider in Stanford, California, licensed in California (A105471) and active in the NPI registry since October 2007. She is enrolled in Medicare PECOS and maintains a secondary practice location in San Francisco.
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 (PECOS)
Dr. Mary P Mercer M.d. is registered in the CMS Provider Enrollment, Chain and Ownership System (PECOS).
Medicare Billing Reassignment
Medicare enrollment records show Mary Mercer reassigns Medicare billing to 1 organization. The organization bills Medicare for the services this provider delivers there.
San Francisco, CA 94110
- Reassigned Medicare billing, California enrollment
- 842 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 3
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 94305 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.
STANFORD, CA 94305
STANFORD, CA 94305
STANFORD, CA 94305
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 Mercer's NPI number?
The NPI number for Mary Mercer is 1104014265. It was assigned to this individual provider in the NPPES registry on October 12, 2007.
Where is Mary Mercer located?
Mary Mercer practices at 300 Pasteur Dr, Stanford, CA 94305. The listed phone number is (650) 723-4000.
What is Mary Mercer's specialty?
The primary specialty registered for this NPI is Emergency Medicine with taxonomy code 207P00000X.
Is Mary Mercer enrolled in Medicare?
Yes. Mary Mercer is registered in the Medicare PECOS enrollment system.
Which organization bills Medicare for Mary Mercer's services?
According to the CMS Revalidation Reassignment List (October 2026 release), Mary Mercer reassigns Medicare benefits to University Of California Sfgh Medical Group (San Francisco, CA). The 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 Mercer'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 Mercer was last updated on June 12, 2026. NPI Profile syncs weekly with the NPPES registry data releases published by CMS. This NPI record was last updated 4 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.
# Dr. Mary P Mercer, M.D. · NPI 1104014265
Emergency Medicine physician in Stanford, California. Individual provider, active in the CMS NPPES registry since October 12, 2007.
## Identity
- **NPI:** 1104014265 (Entity type: Individual)
- **Enumerated:** October 12, 2007
- **Primary specialty:** Emergency Medicine · taxonomy 207P00000X
- **State license:** A105471 (California)
- **Sole proprietor:** No
## Practice location
- **Address:** 300 PASTEUR DR, Stanford, CA 94305-2200
- **Phone:** (650) 723-4000
## Medicare
- **Medicare:** Enrolled in Medicare (PECOS)
- **Ordering & referring:** eligible for Part B labs & imaging, durable medical equipment, home health, power mobility devices
- **Bills Medicare through:** University Of California Sfgh Medical Group (NPI 1174598296, San Francisco, CA), under Medicare reassignment (form CMS-855R) · CMS Revalidation Reassignment List, October 2026 release
## Record status
- **NPPES last updated:** June 12, 2026
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Source: [NPI Profile](https://npiprofile.com/npi/1104014265) · Data from the CMS NPPES public registry.