LESLIE GRAUSTARK OESTERICH
NPI 1245518422
Internal Medicine in Torrance, CA
About Leslie Graustark Oesterich NPPES
Official registry information on file with the National Plan and Provider Enumeration System.
LESLIE GRAUSTARK OESTERICH (NPI 1245518422) is an individual internal medicine provider in Torrance, California, licensed in California (A125675) and active in the NPI registry since July 2011. She is enrolled in Medicare PECOS and is a graduate of University Of California, Geffen School Of Medicine (2011).
NPPES Registry Identity
Specialties & Licenses
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
Leslie Graustark Oesterich 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 Leslie Oesterich reassigns Medicare billing to 2 organizations. Each organization bills Medicare for the services this provider delivers there; the nearest is listed first.
Torrance, CA 90502
- Reassigned Medicare billing, California enrollment
- 1,939 clinicians in this Medicare group
Santa Clara, CA 95051
- Reassigned Medicare billing, California enrollment
- 20,078 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 90509 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 8
Providers registered at the same practice address, or within the immediate area, according to the NPPES registry.
TORRANCE, CA 90509
TORRANCE, CA 90509
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 Leslie Oesterich's NPI number?
The NPI number for Leslie Oesterich is 1245518422. It was assigned to this individual provider in the NPPES registry on July 22, 2011.
Where is Leslie Oesterich located?
Leslie Oesterich practices at 1000 W Carson St. Box 400, Torrance, CA 90509. The listed phone number is (310) 222-2401.
What is Leslie Oesterich's specialty?
The primary specialty registered for this NPI is Internal Medicine with taxonomy code 207R00000X.
Is Leslie Oesterich enrolled in Medicare?
Yes. Leslie Oesterich 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 Leslie Oesterich's services?
According to the CMS Revalidation Reassignment List (October 2026 release), Leslie Oesterich reassigns Medicare benefits to 2 organizations: County Of Los Angeles (Torrance, CA) and Permanente Medical Group Inc (Santa Clara, 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 Leslie Oesterich'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 Leslie Oesterich was last updated on February 11, 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.
# Leslie Graustark Oesterich · NPI 1245518422
Internal Medicine physician in Torrance, California. Individual provider, active in the CMS NPPES registry since July 22, 2011.
## Identity
- **NPI:** 1245518422 (Entity type: Individual)
- **Enumerated:** July 22, 2011
- **Primary specialty:** Internal Medicine · taxonomy 207R00000X
- **State license:** A125675 (California)
- **Sole proprietor:** Yes
## Practice location
- **Address:** 1000 W CARSON ST., BOX 400, Torrance, CA 90509
- **Phone:** (310) 222-2401
## 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): County Of Los Angeles (NPI 1851363188, Torrance, CA); Permanente Medical Group Inc (NPI 1073606299, Santa Clara, CA) · CMS Revalidation Reassignment List, October 2026 release
- **Medical school:** University Of California, Geffen School Of Medicine, class of 2011
## Record status
- **NPPES last updated:** February 11, 2022
---
Source: [NPI Profile](https://npiprofile.com/npi/1245518422) · Data from the CMS NPPES public registry.