Leslie Graustark Oesterich
Internal Medicine Physician · Torrance, CA
Leslie Graustark Oesterich is an internal medicine physician with a practice address in Torrance, California, and NPI 1245518422, issued on Jul 22, 2011. Check the license (California A125675, as entered in NPPES) on the Medical Board of California; the Medicare figures below come from public CMS files.
- Name
- Leslie Graustark Oesterich
- Primary taxonomy
- Internal Medicine Physician 207R00000X
- License number
- A125675 CA
Self-reported in NPPES; status is on the state search - Practice location
- 1000 W Carson St., Torrance, CA 90509
- Phone
- (310) 222-2401
- Enumerated
- Jul 22, 2011
- Record last updated
- Feb 11, 2022
- Medicare enrollment
- Enrolled (PECOS I20140711000015); accepts Medicare assignment
- Medical or professional school
- University Of California, Geffen School Of Medicine, 2011
- Entity
- Type 1 · individual
8 nearest internal medicine physician records → All 17,696 in California → Look up another NPI →
Also registered at 1000 W Carson St.
A shared address usually means a shared clinic or building; it does not show who employs whom.
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- Caroline Miranda, LCSWSocial Worker1952327207
- Sharareh ShahangianCritical Care Medicine (Internal Medicine) Physician1144508326
Verify Leslie Graustark Oesterich in five checks
- 1IdentityNPI record in CMS NPPESNPI lookupConfirmed in NPPES
- 2LicenseActive license and public ordersMedical Board of California
Search for license A125675Check the board - 3Other statesLicenses and actions elsewhereDocInfo (FSMB)Not checked
- 4ExclusionsMedicare and Medicaid bansHHS-OIG exclusion listNot checked
- 5CertificationBoard certificationABMS AOA NCCPA AANPNot checked
68% fewer Medicare Part D claims than the average internal medicine physician in 2024
1,022 Medicare Part D claims for 142 beneficiaries, against an average of 3,176 among the 108,855 providers of this specialty who prescribed in Part D. Brand-name drugs were 28% of claims.
Most prescribed
- Lenalidomide126 claims
- Dexamethasone119 claims
- Acyclovir86 claims
- Brukinsa85 claims
- Hydroxyurea63 claims
- Prednisone62 claims
Source: CMS Medicare Part D Prescribers by Provider and Drug, 2024 (data.cms.gov). Part D covers prescriptions for Medicare patients only; drugs with fewer than 11 claims are not published.
Bills Medicare through one group practice
- Permanente Medical Group IncRedwood City, CA
Source: CMS Doctors and Clinicians National Downloadable File (the group practices a clinician bills Medicare through) (data.cms.gov).
Leslie Graustark Oesterich among 17,696 internal medicine physician records in California
Leslie Graustark Oesterich is one of 17,696 internal medicine physician records with a practice address in California. 79% of them appear in a Medicare file (Part D prescribing, MIPS, Open Payments or Medicare group billing); this one does. Its NPI, issued in 2011, is newer than 66% of them.
- NPI issued2011 · 66% of these records are older, 32% newer
- In a Medicare fileYes · 79% of these records are
- In the CMS Doctors and Clinicians fileYes · 63% of these records are
- Graduated2011 · median 2004 among the 11,065 with a school on file
- Record last updated2022 · 61% of these records were not updated in five years or more
Source: CMS NPPES, file of Aug 9, 2026, every record with primary taxonomy 207R00000X and a California practice address; Medicare files: CMS Part D Prescribers 2024, MIPS 2023, Open Payments 2024, Doctors and Clinicians (data.cms.gov).
231 internal medicine physician records list a practice address in Torrance
They are 231 of the 8,901 NPPES records with a practice address in Torrance, and 17,696 internal medicine physician records in California.
All 17,696 in California → Every provider in Torrance → Internal Medicine Physician nationwide →
The 8 internal medicine physician records with the nearest ZIP codes
- Antonio Bonet, MDTorrance, CA 905091134386956
- Christopher Brown, MD, MPHTorrance, CA 905091609123504
- Albert Cespedes, M.D.Torrance, CA 905091942527650
- Lisa Chung, M.D.Torrance, CA 905091083931794
- Anuj Datta, MDTorrance, CA 905091215129416
- Ritu Kumar, M.D.Torrance, CA 905091063535367
- Patricia Loo, MDTorrance, CA 905091427215250
- Carmen Mendez, M.D.Torrance, CA 905091609073618
Common questions
What is Leslie Graustark Oesterich's NPI number?
Leslie Graustark Oesterich's National Provider Identifier (NPI) is 1245518422, issued on Jul 22, 2011. An NPI identifies a provider in billing; it is not a license.
Where is Leslie Graustark Oesterich located?
The NPPES record lists a practice address at 1000 W Carson St., Torrance, CA, 90509. Phone: (310) 222-2401. Providers update this record themselves, so call before visiting.
How can I verify Leslie Graustark Oesterich's license?
NPPES lists California license number A125675, as entered by the provider. Search the Medical Board of California at https://www.mbc.ca.gov/License-Verification/default.aspx. The NPPES record confirms identity only; the state search shows license status, expiration and public orders.
How much does Leslie Graustark Oesterich prescribe under Medicare Part D?
In 2024, Leslie Graustark Oesterich had 1,022 Medicare Part D claims for 142 beneficiaries; the average among internal medicine physician prescribers was 3,176. Part D covers Medicare prescriptions only.
Source: CMS National Plan and Provider Enumeration System (NPPES), file of Aug 9, 2026 (NPPES files on CMS.gov); NUCC Health Care Provider Taxonomy. Medicare files from data.cms.gov. An NPI identifies who bills; it is not a license.
Figures on PlainDoctor are read from the federal files each page names (CMS NPPES, Medicare Part D, MIPS, Open Payments; the HHS-OIG exclusion list only as counts) and from Census population estimates, with the file date shown beside them. See our editorial standards & corrections policy, the methodology behind these numbers, or report a data error. Data current as of Aug 9, 2026.