NPPES file of Aug 9, 2026

Jeffrey Ahn, M.D.

Hematology & Oncology Physician · Orange, CA

Jeffrey Ahn, M.D. is a hematology & oncology physician with a practice address in Orange, California, and NPI 1902331630, issued on May 1, 2017. Check the license (California A159137, 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 · method · Verify with CMS →

NPPES recordNPPES file of Aug 9, 2026
1902331630
Name
Jeffrey Ahn
Credential
M.D.
Primary taxonomy
Hematology & Oncology Physician 207RH0003X
License number
A159137 CA
Self-reported in NPPES; status is on the state search
Practice location
101 The City Dr S, Orange, CA 92868
Phone
(714) 456-8100
Enumerated
May 1, 2017
Record last updated
Jul 31, 2024
Medicare enrollment
Enrolled (PECOS I20240808000684); accepts Medicare assignment
Telehealth
Offers telehealth (CMS)
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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8 nearest hematology & oncology physician records → All 1,583 in California → Look up another NPI →

Also registered at 101 The City Dr S

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

  1. Danny Abad, PAPhysician Assistant1477158673
  2. Edward AbaradoStudent in an Organized Health Care Education/Training Program1912855198
  3. Nagina Abdiani, DOGeriatric Medicine (Family Medicine) Physician1518543271
  4. Mariam Abdul-Latif, M.D.Pediatrics Physician1538418884
  5. Eric AbelloOtolaryngology Physician1922566215
  6. Brandon Abeyta, MDAnesthesiology Physician1841291804

Verify Jeffrey Ahn in five checks

  1. 1IdentityNPI record in CMS NPPESNPI lookupConfirmed in NPPES
  2. 2LicenseActive license and public ordersMedical Board of California
    Search for license A159137    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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Bills Medicare through one group practice

  1. UC RegentsOrange, CA

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

Jeffrey Ahn among 1,583 hematology & oncology physician records in California

Jeffrey Ahn, M.D. is one of 1,583 hematology & oncology physician records with a practice address in California. 83% of them appear in a Medicare file (Part D prescribing, MIPS, Open Payments or Medicare group billing); this one does. Its NPI, issued in 2017, is newer than 89% of them.

  • NPI issued2017 · 89% of these records are older, 8% newer
  • In a Medicare fileYes · 83% of these records are
  • In the CMS Doctors and Clinicians fileYes · 71% of these records are
  • Graduated2017 · median 2003 among the 1,124 with a school on file
  • Record last updated2024 · 58% of these records were not updated in five years or more

Source: CMS NPPES, file of Aug 9, 2026, every record with primary taxonomy 207RH0003X and a California practice address; Medicare files: CMS Part D Prescribers 2024, MIPS 2023, Open Payments 2024, Doctors and Clinicians (data.cms.gov).

Hematology & Oncology Physician providers in California

There are 1,583 hematology & oncology physician records in California.

All 1,583 in California → Every provider in Orange → Hematology & Oncology Physician nationwide →

The 8 hematology & oncology physician records with the nearest ZIP codes

  1. Timothy Byun, MDOrange, CA 928681871545012
  2. Warren Chow, MDOrange, CA 928681093822017
  3. Paul Coluzzi, M.D.Orange, CA 928681972563906
  4. Mihaela Cristea, MDOrange, CA 928681417050998
  5. Sam Huang, M.D.Orange, CA 928681841248812
  6. Tiberio Lindgren, MDOrange, CA 928681275585424
  7. John Link, MDOrange, CA 928681245281211
  8. Steven Lipkin, MDOrange, CA 928681134153547

Common questions

What is Jeffrey Ahn, M.D.'s NPI number?

Jeffrey Ahn, M.D.'s National Provider Identifier (NPI) is 1902331630, issued on May 1, 2017. An NPI identifies a provider in billing; it is not a license.

Where is Jeffrey Ahn, M.D. located?

The NPPES record lists a practice address at 101 The City Dr S, Orange, CA, 92868. Phone: (714) 456-8100. Providers update this record themselves, so call before visiting.

How can I verify Jeffrey Ahn, M.D.'s license?

NPPES lists California license number A159137, 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.

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.

Written with AI tools from the named public files; every figure is computed from those files (how it is made).

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.