Barnett J. W. Grier, M.D.
Internal Medicine Physician · Los Angeles, CA
Barnett J. W. Grier, M.D. is an internal medicine physician with a practice address in Los Angeles, California, and NPI 1932233665, issued on Mar 15, 2007. Check the license (California A23617, as entered in NPPES) on the Medical Board of California; the Medicare figures below come from public CMS files.
- Name
- Barnett J. W. Grier
- Credential
- M.D.
- Primary taxonomy
- Internal Medicine Physician 207R00000X
- License number
- A23617 CA
Self-reported in NPPES; status is on the state search - Practice location
- 231 W Vernon Ave Ste 201, Los Angeles, CA 90037
- Phone
- (323) 828-7929
- Enumerated
- Mar 15, 2007
- Record last updated
- Jul 10, 2022
- Medicare enrollment
- Enrolled (PECOS I20230301002237); accepts Medicare assignment
- Medical or professional school
- University Of California, Geffen School Of Medicine, 1968
- Telehealth
- Offers telehealth (CMS)
- Entity
- Type 1 · individual
8 nearest internal medicine physician records → All 17,696 in California → Look up another NPI →
Verify Barnett J. W. Grier in five checks
- 1IdentityNPI record in CMS NPPESNPI lookupConfirmed in NPPES
- 2LicenseActive license and public ordersMedical Board of California
Search for license A23617Check the board - 3Other statesLicenses and actions elsewhereDocInfo (FSMB)Not checked
- 4ExclusionsMedicare and Medicaid bansHHS-OIG exclusion listNot checked
- 5CertificationBoard certificationABMS AOA NCCPA AANPNot checked
67% more Medicare Part D claims than the average internal medicine physician in 2024
5,306 Medicare Part D claims for 304 beneficiaries, against an average of 3,176 among the 108,855 providers of this specialty who prescribed in Part D. Brand-name drugs were 16% of claims. 355 claims were for opioids.
Most prescribed
- Atorvastatin Calcium294 claims
- Losartan Potassium254 claims
- Amlodipine Besylate196 claims
- Hydrocodone-Acetaminophen189 claims
- Lisinopril186 claims
- Omeprazole160 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 2 group practices
- Apogee Health Solutions LpcRiverside, CA
- Eastern Plumas Health Care DistrictPortola, CA
Source: CMS Doctors and Clinicians National Downloadable File (the group practices a clinician bills Medicare through) (data.cms.gov).
Barnett J. W. Grier among 17,696 internal medicine physician records in California
Barnett J. W. Grier, M.D. 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 2007, is newer than 44% of them.
- NPI issued2007 · 44% of these records are older, 44% newer
- In a Medicare fileYes · 79% of these records are
- In the CMS Doctors and Clinicians fileYes · 63% of these records are
- Graduated1968 · 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).
1,423 internal medicine physician records list a practice address in Los Angeles
They are 1,423 of the 69,537 NPPES records with a practice address in Los Angeles, and 17,696 internal medicine physician records in California.
All 17,696 in California → Every provider in Los Angeles → Internal Medicine Physician nationwide →
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- Xiaomei Lin, MDLos Angeles, CA 900371295198810
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- Shiny Varghese, MDLos Angeles, CA 900371134534308
- Damon Forbes, M.D.Los Angeles, CA 900361932335452
- George Fouladian, M.D.Los Angeles, CA 900361932204161
Common questions
What is Barnett J. W. Grier, M.D.'s NPI number?
Barnett J. W. Grier, M.D.'s National Provider Identifier (NPI) is 1932233665, issued on Mar 15, 2007. An NPI identifies a provider in billing; it is not a license.
Where is Barnett J. W. Grier, M.D. located?
The NPPES record lists a practice address at 231 W Vernon Ave Ste 201, Los Angeles, CA, 90037. Phone: (323) 828-7929. Providers update this record themselves, so call before visiting.
How can I verify Barnett J. W. Grier, M.D.'s license?
NPPES lists California license number A23617, 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 Barnett J. W. Grier, M.D. prescribe under Medicare Part D?
In 2024, Barnett J. W. Grier, M.D. had 5,306 Medicare Part D claims for 304 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.