Eugene Byun, MD
Eugene Byun, MD is an Interventional Cardiology Physician in Fullerton, CA, registered under NPI 1104812643. This provider registers 3 separate taxonomy codes, which usually means they practise across more than one recognised specialty.
Getting there
The practice address on file is 100 E VALENCIA MESA DR SUITE 206, Fullerton, CA 92835. We have not yet mapped what surrounds this office — parking, transit, and nearby pharmacies are added as our data collection reaches each location.
Credentials and Medicare
| Licence | State | Specialty |
|---|---|---|
| G82180 | CA | Interventional Cardiology Physician primary |
| G82180 | CA | Cardiovascular Disease Physician |
| G82180 | CA | Internal Medicine Physician |
This provider holds licence G82180 issued in CA. A licence number in NPPES reflects what was filed at registration — it does not confirm the licence is still active today.
- Status
- Approved
- Provider type
- Practitioner - Cardiovascular Disease (cardiology)
- PAC ID
- 1456482330
Medicare enrolment is recorded as approved under the provider type Practitioner - Cardiovascular Disease (cardiology). This means the provider is enrolled to bill Medicare, though it does not tell you whether they are currently accepting new Medicare patients. Call the office to confirm.
What Interventional Cardiology covers
An area of medicine within the subspecialty of cardiology, which uses specialized imaging and other diagnostic techniques to evaluate blood flow and pressure in the coronary arteries and chambers of the heart and uses technical procedures and medications to treat abnormalities that impair the function of the cardiovascular system. NUCC Health Care Provider Taxonomy, code 207RI0011X
All registered taxonomy codes
This provider registers 3 taxonomy codes. The primary code is what appears on most claims; the others record additional recognised specialties.
| Code | Specialty | Licence | State | |
|---|---|---|---|---|
| 207RI0011X | Interventional Cardiology Physician Interventional Cardiology | G82180 | CA | primary |
| 207RC0000X | Cardiovascular Disease Physician Cardiovascular Disease | G82180 | CA | |
| 207R00000X | Internal Medicine Physician | G82180 | CA |
The taxonomy records how the provider classifies their own practice. It does not confirm which conditions they currently treat, whether they are accepting new patients, or which insurance they take — call the office for that.
Full NPPES record
An NPI-1 identifies a single person. It stays with the clinician for life, even if they move practice or change state, which is why the address on file can lag behind where they actually work today.
| NPI | 1104812643 valid check digit |
|---|---|
| Entity type | Individual (NPI-1) |
| Enumeration date | Sep 20, 2005 |
| Last updated | Mar 6, 2026 |
| Status | Active |
| Sole proprietor | No |
| Credential | MD |
| Practice address |
100 E VALENCIA MESA DR SUITE 206 Fullerton, CA 92835 (714) 446-5050 Fax (714) 446-5150 |
| Mailing address |
100 E VALENCIA MESA DR STE 206 Fullerton, CA 92835 |
Number check
How the check works, step by step
Every NPI carries a Luhn check digit — the same scheme used on credit cards. CMS prefixes the number with 80840 before computing it, which marks it as a US health identifier.
| Digit | 8 | 0 | 8 | 4 | 0 | 1 | 1 | 0 | 4 | 8 | 1 | 2 | 6 | 4 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Doubled? | — | ×2 | — | ×2 | — | ×2 | — | ×2 | — | ×2 | — | ×2 | — | ×2 |
| Value | 8 | 0 | 8 | 8 | 0 | 2 | 1 | 0 | 4 | 7 | 1 | 4 | 6 | 8 |
Sum = 57 · next multiple of 10 = 60 · check digit = 3 · actual last digit = 3
A valid check digit only means the number is well-formed. It does not mean the provider is licensed, active, or in good standing — those are separate questions answered by the sections above.