OMAR A MESARWI MD
NPI 1245430032
Internal Medicine - Critical Care Medicine in San Diego, CA
About Omar A Mesarwi Md NPPES
Official registry information on file with the National Plan and Provider Enumeration System.
OMAR A MESARWI MD (NPI 1245430032) is an individual critical care medicine provider in San Diego, California, licensed in California (A144727) and active in the NPI registry since July 2007. He is enrolled in Medicare PECOS, maintains 2 additional practice locations, and is a graduate of University Of Texas Southwestern Medical School At Dallas (2007).
NPPES Registry Identity
Specialties & Licenses 3
Secondary Practice Locations 2
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
Omar A Mesarwi 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 Reassignment
Medicare enrollment records show Omar Mesarwi reassigns Medicare billing to 1 organization. The organization bills Medicare for the services this provider delivers there.
San Diego, CA 92103
- Reassigned Medicare billing, California enrollment
- Also billed through NPI 1386762300 (California)
- 1,051 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 7
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 92121 ZIP code area, from fee-for-service claims. These are area statistics, not this provider’s prices; actual charges vary by service and coverage.
Referred Medical Equipment & Supplies CMS DME claims 11
Durable medical equipment, devices and supplies this provider ordered from DME suppliers for patients, from Medicare fee-for-service claims.
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 DIEGO, CA 92121
SAN DIEGO, CA 92121
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 Omar Mesarwi's NPI number?
The NPI number for Omar Mesarwi is 1245430032. It was assigned to this individual provider in the NPPES registry on July 20, 2007.
Where is Omar Mesarwi located?
Omar Mesarwi practices at 4520 Executive Dr, San Diego, CA 92121. The listed phone number is (800) 926-8273.
What is Omar Mesarwi's specialty?
The primary specialty registered for this NPI is Internal Medicine, specializing in Critical Care Medicine, with taxonomy code 207RC0200X.
Is Omar Mesarwi enrolled in Medicare?
Yes. Omar Mesarwi 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 organization bills Medicare for Omar Mesarwi's services?
According to the CMS Revalidation Reassignment List (October 2026 release), Omar Mesarwi reassigns Medicare benefits to Regents Of The University Of California (San Diego, 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 Omar Mesarwi'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 Omar Mesarwi was last updated on June 10, 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.
# Omar A Mesarwi, MD · NPI 1245430032
Critical Care Medicine physician in San Diego, California. Individual provider, active in the CMS NPPES registry since July 20, 2007.
## Identity
- **NPI:** 1245430032 (Entity type: Individual)
- **Enumerated:** July 20, 2007
- **Primary specialty:** Internal Medicine - Critical Care Medicine · taxonomy 207RC0200X
- **State license:** A144727 (California)
- **Sole proprietor:** No
## Practice location
- **Address:** 4520 EXECUTIVE DR, San Diego, CA 92121-3018
- **Phone:** (800) 926-8273
## 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:** Regents Of The University Of California (NPI 1487772380, San Diego, CA), under Medicare reassignment (form CMS-855R) · CMS Revalidation Reassignment List, October 2026 release
- **Medical school:** University Of Texas Southwestern Medical School At Dallas, class of 2007
## Record status
- **NPPES last updated:** June 10, 2026
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Source: [NPI Profile](https://npiprofile.com/npi/1245430032) · Data from the CMS NPPES public registry.