Ja Eun Koo
Internal Medicine Physician · Loma Linda, CA
Ja Eun Koo is an internal medicine physician with a practice address in Loma Linda, California, and NPI 1558700187, issued on Jun 17, 2013. Check the license (California A137368, as entered in NPPES) on the Medical Board of California; the Medicare figures below come from public CMS files.
- Name
- Ja Eun Koo
- Primary taxonomy
- Internal Medicine Physician 207R00000X
- License number
- A137368 CA
Self-reported in NPPES; status is on the state search - Practice location
- 11234 Anderson St, Loma Linda, CA 92354
- Phone
- (909) 558-4000
- Enumerated
- Jun 17, 2013
- Record last updated
- Jul 1, 2018 (not updated in 8 years: call before relying on the address or phone)
- Medicare enrollment
- Enrolled (PECOS I20180529002884); accepts Medicare assignment
- Medical or professional school
- West Virginia University School Of Medicine, 2013
- Entity
- Type 1 · individual
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Also registered at 11234 Anderson St
A shared address usually means a shared clinic or building; it does not show who employs whom.
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Verify Ja Eun Koo in five checks
- 1IdentityNPI record in CMS NPPESNPI lookupConfirmed in NPPES
- 2LicenseActive license and public ordersMedical Board of California
Search for license A137368Check the board - 3Other statesLicenses and actions elsewhereDocInfo (FSMB)Not checked
- 4ExclusionsMedicare and Medicaid bansHHS-OIG exclusion listNot checked
- 5CertificationBoard certificationABMS AOA NCCPA AANPNot checked
91% fewer Medicare Part D claims than the average internal medicine physician in 2024
294 Medicare Part D claims for 96 beneficiaries, against an average of 3,176 among the 108,855 providers of this specialty who prescribed in Part D. 26 claims were for opioids.
Most prescribed
- Ondansetron Hcl14 claims
- Famotidine13 claims
- Hydrocodone-Acetaminophen12 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.
The practice group's MIPS final score for 2023 (Medicare payment program): 85.2 of 100
The Merit-based Incentive Payment System score is reported for the practice group, not for one clinician alone. Four categories are weighted into the final score; the average among 454,083 clinicians with a measured score was 83.5.
Source: CMS Quality Payment Program, MIPS performance year 2023, group reporting; category weights for 2023 (qpp.cms.gov).
Bills Medicare through one group practice
- Faculty Physicians And Surgeons OF LlusmRedlands, CA
Source: CMS Doctors and Clinicians National Downloadable File (the group practices a clinician bills Medicare through) (data.cms.gov).
Ja Eun Koo among 17,696 internal medicine physician records in California
Ja Eun Koo 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 2013, is newer than 71% of them.
- NPI issued2013 · 71% of these records are older, 26% newer
- In a Medicare fileYes · 79% of these records are
- In the CMS Doctors and Clinicians fileYes · 63% of these records are
- Graduated2013 · median 2004 among the 11,065 with a school on file
- Record last updated2018 · 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).
212 internal medicine physician records list a practice address in Loma Linda
They are 212 of the 4,863 NPPES records with a practice address in Loma Linda, and 17,696 internal medicine physician records in California.
All 17,696 in California → Every provider in Loma Linda → Internal Medicine Physician nationwide →
The 8 internal medicine physician records with the nearest ZIP codes
- David Baylink, M.D.Loma Linda, CA 923541518983113
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- Debra Craig, M.D.Loma Linda, CA 923541255351151
- Balu Gadhe, M.D.Loma Linda, CA 923541740233808
- Bevan Geslani, M.D.Loma Linda, CA 923541992741862
- Susan Hall, M.D.Loma Linda, CA 923541972523876
- Suchaya Jinamornphongs, M.D.Loma Linda, CA 923541649299876
Common questions
What is Ja Eun Koo's NPI number?
Ja Eun Koo's National Provider Identifier (NPI) is 1558700187, issued on Jun 17, 2013. An NPI identifies a provider in billing; it is not a license.
Where is Ja Eun Koo located?
The NPPES record lists a practice address at 11234 Anderson St, Loma Linda, CA, 92354. Phone: (909) 558-4000. Providers update this record themselves, so call before visiting.
How can I verify Ja Eun Koo's license?
NPPES lists California license number A137368, 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 Ja Eun Koo prescribe under Medicare Part D?
In 2024, Ja Eun Koo had 294 Medicare Part D claims for 96 beneficiaries; the average among internal medicine physician prescribers was 3,176. Part D covers Medicare prescriptions only.
What is Ja Eun Koo's MIPS final score?
The 2023 MIPS final score is 85.2 of 100, reported for the practice group. The average among 454,083 clinicians with a measured score was 83.5.
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.