Oana L. Klein, MD
Internal Medicine Physician · Larkspur, CA
Oana L. Klein, MD is an internal medicine physician with a practice address in Larkspur, California, and NPI 1427240647, issued on Aug 11, 2007. Check the license (California C54895, as entered in NPPES) on the Medical Board of California; the Medicare figures below come from public CMS files.
- Name
- Oana L. Klein
- Credential
- MD
- Primary taxonomy
- Internal Medicine Physician 207R00000X
- License numbers
- C54895 CA
036-119158 IL
Self-reported in NPPES; status is on the state search - Practice location
- 5 Bon Air RD Ste 117, Larkspur, CA 94939
- Phone
- (415) 448-1500
- Enumerated
- Aug 11, 2007
- Record last updated
- Mar 15, 2023
- Entity
- Type 1 · individual
8 nearest internal medicine physician records → All 17,696 in California → Look up another NPI →
Also registered at 5 Bon Air RD Ste 117
A shared address usually means a shared clinic or building; it does not show who employs whom.
- Alaric Akashi, MDInternal Medicine Physician1285784264
- Dylan Bellavance, DOFamily Medicine Physician1013414507
- Mykaela PoePhysician Assistant1861357147
Verify Oana L. Klein in five checks
- 1IdentityNPI record in CMS NPPESNPI lookupConfirmed in NPPES
- 2LicenseActive license and public ordersMedical Board of California
Search for license C54895Check the board - 3Other statesLicenses and actions elsewhereDocInfo (FSMB)Not checked
- 4ExclusionsMedicare and Medicaid bansHHS-OIG exclusion listNot checked
- 5CertificationBoard certificationABMS AOA NCCPA AANPNot checked
63% fewer Medicare Part D claims than the average internal medicine physician in 2024
1,164 Medicare Part D claims for 147 beneficiaries, against an average of 3,176 among the 108,855 providers of this specialty who prescribed in Part D. 13 claims were for opioids.
Most prescribed
- Atorvastatin Calcium128 claims
- Levothyroxine Sodium85 claims
- Amlodipine Besylate62 claims
- Losartan Potassium46 claims
- Metformin Hcl44 claims
- Gabapentin30 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.
Industry payments in 2024: $24.62
1 payment: food and beverage; the largest payer was Novo Nordisk Inc. The 50,334 providers of this specialty with any payment received $1,303.06 on average. Payments are reported by manufacturers, not by the provider, and are not a sign of wrongdoing.
Source: CMS Open Payments, program year 2024 (openpaymentsdata.cms.gov); average among providers of this specialty with at least one payment.
Oana L. Klein among 17,696 internal medicine physician records in California
Oana L. Klein, MD 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 fileNo · 63% of these records are
- Record last updated2023 · 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).
7 internal medicine physician records list a practice address in Larkspur
They are 7 of the 291 NPPES records with a practice address in Larkspur, and 17,696 internal medicine physician records in California.
All 17,696 in California → Every provider in Larkspur → Internal Medicine Physician nationwide →
The 8 internal medicine physician records with the nearest ZIP codes
- Alaric Akashi, MDLarkspur, CA 949391285784264
- Katherine Chick, M.DLarkspur, CA 949391386855567
- Robert DorisLarkspur, CA 949391528647096
- Marvin Freid, M.D.Larkspur, CA 949391639602923
- Rosalind Hudson, M.D.Larkspur, CA 949391528122900
- Willie Tang, MDLarkspur, CA 949391215513890
- Holly Batterman, M.D.Mill Valley, CA 949411124138276
- Kathy Chang-Lipsenthal, MDMill Valley, CA 949411356340079
Common questions
What is Oana L. Klein, MD's NPI number?
Oana L. Klein, MD's National Provider Identifier (NPI) is 1427240647, issued on Aug 11, 2007. An NPI identifies a provider in billing; it is not a license.
Where is Oana L. Klein, MD located?
The NPPES record lists a practice address at 5 Bon Air RD Ste 117, Larkspur, CA, 94939. Phone: (415) 448-1500. Providers update this record themselves, so call before visiting.
How can I verify Oana L. Klein, MD's license?
NPPES lists California license number C54895, 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 Oana L. Klein, MD prescribe under Medicare Part D?
In 2024, Oana L. Klein, MD had 1,164 Medicare Part D claims for 147 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.