MS. ROSEMARIE BUSTOS DIAZ
NPI 1215317441
Emergency Medicine in Santa Monica, CA
About Ms. Rosemarie Bustos Diaz NPPES
Official registry information on file with the National Plan and Provider Enumeration System.
MS. ROSEMARIE BUSTOS DIAZ (NPI 1215317441) is an individual emergency medicine provider in Santa Monica, California, licensed in California (A171845) and active in the NPI registry since June 2015. She is enrolled in Medicare PECOS and maintains a secondary practice location in Los Angeles.
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 (PECOS)
Ms. Rosemarie Bustos Diaz is registered in the CMS Provider Enrollment, Chain and Ownership System (PECOS).
Medicare Billing Reassignments
5Medicare enrollment records show Rosemarie Diaz reassigns Medicare billing to 5 organizations. Each organization bills Medicare for the services this provider delivers there; the nearest is listed first.
Santa Monica, CA 90404
- Reassigned Medicare billing, California enrollment
- 1,204 clinicians in this Medicare group
Santa Monica, CA 90405
- Reassigned Medicare billing, California enrollment
- 1,939 clinicians in this Medicare group
Los Angeles, CA 90095
- Reassigned Medicare billing, California enrollment
- 135 clinicians in this Medicare group
Northridge, CA 91325
- Reassigned Medicare billing, California enrollment
- 137 clinicians in this Medicare group
Los Angeles, CA 90033
- Reassigned Medicare billing, California enrollment
- 100 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 4
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 90404 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.
SANTA MONICA, CA 90404
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 Rosemarie Diaz's NPI number?
The NPI number for Rosemarie Diaz is 1215317441. It was assigned to this individual provider in the NPPES registry on June 3, 2015.
Where is Rosemarie Diaz located?
Rosemarie Diaz practices at 1250 16th St, Santa Monica, CA 90404. The listed phone number is (310) 794-7700.
What is Rosemarie Diaz's specialty?
The primary specialty registered for this NPI is Emergency Medicine with taxonomy code 207P00000X.
Is Rosemarie Diaz enrolled in Medicare?
Yes. Rosemarie Diaz is registered in the Medicare PECOS enrollment system.
Which organizations bill Medicare for Rosemarie Diaz's services?
According to the CMS Revalidation Reassignment List (October 2026 release), Rosemarie Diaz reassigns Medicare benefits to 5 organizations: Cep America - California (Santa Monica, CA), County Of Los Angeles (Santa Monica, CA), Regents Of The Univ Of Ca Emer Med (Los Angeles, CA), Ridgeline Emergency Physicians Medical Group, Inc. (Northridge, CA) and Victory Emergency Physicians Medical Group Inc (Los Angeles, 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 Rosemarie Diaz'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 Rosemarie Diaz was last updated on April 12, 2023. NPI Profile syncs weekly with the NPPES registry data releases published by CMS. This NPI record was last updated 3 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.
# Ms. Rosemarie Bustos Diaz · NPI 1215317441
Emergency Medicine physician in Santa Monica, California. Individual provider, active in the CMS NPPES registry since June 3, 2015.
## Identity
- **NPI:** 1215317441 (Entity type: Individual)
- **Enumerated:** June 3, 2015
- **Primary specialty:** Emergency Medicine · taxonomy 207P00000X
- **State license:** A171845 (California)
- **Sole proprietor:** No
## Practice location
- **Address:** 1250 16TH ST, Santa Monica, CA 90404-1249
- **Phone:** (310) 794-7700
## 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:** 5 organizations under Medicare reassignment (form CMS-855R): Cep America - California (NPI 1063081545, Santa Monica, CA); County Of Los Angeles (NPI 1235323080, Santa Monica, CA); Regents Of The Univ Of Ca Emer Med (NPI 1104889138, Los Angeles, CA); Ridgeline Emergency Physicians Medical Group, Inc. (NPI 1972953230, Northridge, CA); Victory Emergency Physicians Medical Group Inc (NPI 1932402716, Los Angeles, CA) · CMS Revalidation Reassignment List, October 2026 release
## Record status
- **NPPES last updated:** April 12, 2023
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Source: [NPI Profile](https://npiprofile.com/npi/1215317441) · Data from the CMS NPPES public registry.