NPPES file of Aug 9, 2026

Tomoko Okahara, MD

Internal Medicine Physician · Bellflower, CA

Tomoko Okahara, MD is an internal medicine physician with a practice address in Bellflower, California, and NPI 1821140286, issued on Jan 17, 2007. Check the license (California A74633, as entered in NPPES) on the Medical Board of California; the Medicare figures below come from public CMS files.

Record from CMS NPPES, file of Aug 9, 2026 · Medicare files 2024 · method · Verify with CMS →

NPPES recordNPPES file of Aug 9, 2026
1821140286
Name
Tomoko Okahara
Credential
MD
Primary taxonomy
Internal Medicine Physician 207R00000X
License number
A74633 CA
Self-reported in NPPES; status is on the state search
Practice location
9400 Rosecrans Ave, Bellflower, CA 90706
Phone
(562) 461-3000
Enumerated
Jan 17, 2007
Record last updated
Dec 3, 2021 (not updated in 5 years: call before relying on the address or phone)
Medicare enrollment
Enrolled (PECOS I20040121000562); accepts Medicare assignment
Medical or professional school
Boston University School Of Medicine, 1999
Entity
Type 1 · individual
Public record from CMS NPPES (open it on the CMS NPI Registry). Enrollment, assignment, school and telehealth: CMS Doctors and Clinicians file, Aug 2026. A record is not a license: verify it with the state board.
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Also registered at 9400 Rosecrans Ave

A shared address usually means a shared clinic or building; it does not show who employs whom.

  1. Basil Abdelkarim, MDInternal Medicine Physician1003968454
  2. Le Marie Abellon, NPNurse Practitioner1144389867
  3. Adrian Acevedo, MDEmergency Medicine Physician1407923303
  4. Pravin Acharya, MDEmergency Medicine Physician1104993088
  5. Michele Afshar, PAPhysician Assistant1013065952
  6. Maria Agbing-Mamangun, MDPsychiatry Physician1063589984

Verify Tomoko Okahara in five checks

  1. 1IdentityNPI record in CMS NPPESNPI lookupConfirmed in NPPES
  2. 2LicenseActive license and public ordersMedical Board of California
    Search for license A74633
    Check the board
  3. 3Other statesLicenses and actions elsewhereDocInfo (FSMB)Not checked
  4. 4ExclusionsMedicare and Medicaid bansHHS-OIG exclusion listNot checked
  5. 5CertificationBoard certificationABMS AOA NCCPA AANPNot checked
Open the California license search

PlainDoctor does not match the HHS-OIG exclusion list to individual records: most entries carry no NPI. Search the OIG exclusion list by name.

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2.2 times the Medicare Part D claims of the average internal medicine physician in 2024

6,831 Medicare Part D claims for 902 beneficiaries, against an average of 3,176 among the 108,855 providers of this specialty who prescribed in Part D. Brand-name drugs were 9% of claims. 136 claims were for opioids.

  1. Tomoko Okahara6,831
  2. Specialty average3,176

Most prescribed

  1. Atorvastatin Calcium661 claims
  2. Amlodipine Besylate368 claims
  3. Losartan Potassium322 claims
  4. Lisinopril297 claims
  5. Levothyroxine Sodium286 claims
  6. Rosuvastatin Calcium268 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

  1. Southern California Permanente Medical GroupBellflower, CA

Source: CMS Doctors and Clinicians National Downloadable File (the group practices a clinician bills Medicare through) (data.cms.gov).

Tomoko Okahara among 17,696 internal medicine physician records in California

Tomoko Okahara, 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 fileYes · 63% of these records are
  • Graduated1999 · median 2004 among the 11,065 with a school on file
  • Record last updated2021 · 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).

72 internal medicine physician records list a practice address in Bellflower

They are 72 of the 1,468 NPPES records with a practice address in Bellflower, and 17,696 internal medicine physician records in California.

The 8 internal medicine physician records with the nearest ZIP codes

  1. Alem Asrat, MDBellflower, CA 907061801967724
  2. Asha Bisht, MDBellflower, CA 907061568533487
  3. Jane Fealy, MDBellflower, CA 907061700957743
  4. Ghassan Gholmieh, MDBellflower, CA 907061164599064
  5. Calvin Hong, MDBellflower, CA 907061497822316
  6. Rowena Javier, MDBellflower, CA 907061366513285
  7. Chandrabhan Kewalramani, MDBellflower, CA 907061629149521
  8. Charles Kung, M.D.Bellflower, CA 907061922014174

Common questions

What is Tomoko Okahara, MD's NPI number?

Tomoko Okahara, MD's National Provider Identifier (NPI) is 1821140286, issued on Jan 17, 2007. An NPI identifies a provider in billing; it is not a license.

Where is Tomoko Okahara, MD located?

The NPPES record lists a practice address at 9400 Rosecrans Ave, Bellflower, CA, 90706. Phone: (562) 461-3000. Providers update this record themselves, so call before visiting.

How can I verify Tomoko Okahara, MD's license?

NPPES lists California license number A74633, 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 Tomoko Okahara, MD prescribe under Medicare Part D?

In 2024, Tomoko Okahara, MD had 6,831 Medicare Part D claims for 902 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.