EUGENE BYUN MD
NPI 1104812643
Internal Medicine - Interventional Cardiology in Fullerton, CA

NPI Status: Active since September 20, 2005

Contact Information

100 E VALENCIA MESA DR
SUITE 206
FULLERTON, CA
ZIP 92835
Phone: (714) 446-5050
Fax: (714) 446-5150

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  • Individual
  • Male
  • Years of Experience 34
  • Internal Medicine
  • Interventional Cardiology
  • Accepts Medicare Approved Payment
  • PECOS Enrolled

About EUGENE BYUN

This page provides the complete NPI Profile along with additional information for Eugene Byun, an internist established in Fullerton, California with a medical specialization in Internal Medicine, focusing in interventional cardiology and more than 34 years of experience. He graduated from Indiana University School Of Medicine in 1992. The healthcare provider is registered in the NPI registry with number 1104812643 assigned on September 2005. The practitioner's primary taxonomy code is 207RI0011X with license number G82180 (CA). The provider is registered as an individual and his NPI record was last updated March 2026.

NPI
1104812643
Provider Name
EUGENE BYUN MD
Gender
Male
Entity Type
Individual
Location Address
100 E VALENCIA MESA DR SUITE 206 FULLERTON, CA 92835
Location Phone
(714) 446-5050
Location Fax
(714) 446-5150
Mailing Address
100 E VALENCIA MESA DR STE 206 FULLERTON, CA 92835
Mailing Phone
(714) 446-5050
Mailing Fax
(714) 446-5150
Medical School Name
INDIANA UNIVERSITY SCHOOL OF MEDICINE
Graduation Year
1992
Is Sole Proprietor?
No
Enumeration Date
09-20-2005
Last Update Date
03-06-2026
Code Navigator

An internist like Eugene Byun is a physician who has completed an internal medicine residency and is board-certified or board-eligible in an internist specialty. Internists are trained to care for adults of all ages for many different medical conditions. An internist typically monitors chronic physical conditions, identifies acute diseases, provides family planning, provides counseling about wellness and disease prevention, etc.

Location Map

Specialty - Primary Taxonomy

The NPI enumerator requires providers to submit at least one taxonomy code. A taxonomy code is a unique 10-character code that describes the healthcare provider type, classification, and the area of specialization. There could be only one primary taxonomy code per NPI record. For individual NPIs the license data is associated to the taxonomy code.

Classification

Internal Medicine Interventional Cardiology

Taxonomy Code
207RI0011X
Type
Allopathic & Osteopathic Physicians
License No.
G82180
License State
CA
Taxonomy Description
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.

Secondary Taxonomies

The provider has reported to the NPI enumerator additional taxonomy codes. Multiple taxonomy codes may represent subspecialties or other areas of specialization the provider maybe licensed to practice.

No. Taxonomy Code Type Classification /
Specialization
License No. (State)
1207R00000XAllopathic & Osteopathic Physicians

Internal Medicine

G82180 (CA)
2207RC0000XAllopathic & Osteopathic Physicians

Internal Medicine
Cardiovascular Disease

G82180 (CA)

Medicare Participation & PECOS Enrollment Status

Eugene Byun is registered with Medicare and accepts claims assignment, this means the provider accepts the approved amount for the cost of rendered services as full payment. Participating providers may not charge beneficiaries more than the approved amount for their services. Please keep in mind that beneficiaries still have to pay a coinsurance or copayment amount for a visit or service.

Eugene Byun is enrolled in PECOS and is eligible to order or refer health care services for Medicare patients. The provider is eligible to order or refer: Part B Clinical Laboratory and Imaging, Durable Medical Equipment (DME), a Home Health Agency (HHA) and Power Mobility Devices.

What is PECOS?
PECOS is the online Medicare enrollment management system or Provider, Enrollment, Chain and Ownership System. The PECOS system is a database of providers who have registered with CMS as providers or suppliers. PECOS is the primary source of information about verified Medicare professionals. Providers that want to participate in this program need to enroll in PECOS with their NPI number to avoid denied claims.

  • Is the provider registered in PECOS? Yes

  • PECOS PAC ID: 1456482330

    What is the PECOS Associate Control ID?
    A PAC ID is a unique 10-digit number assigned to an individual or organization healthcare provider in PECOS. The PAC ID is used to link together all the provider information, like tax identification numbers and organizational names. A PAC ID can be connected to multiple Enrollment IDs if an individual or organization has enrolled in PECOS more than once.

  • PECOS Enrollment ID: I20100622000646

    What is the Provider Enrollment ID?
    The Enrollment ID is a unique alphanumeric 15-digit code assigned to each new provider's PECOS enrollment application. The Enrollment ID is used to link together all the provider enrollment information like enrollment type, state, provider specialty, and reassignment of benefits.

  • Accepts Medicare Assignment? Yes

    What does it mean "accepts medicare assignment"?
    When a provider accepts Medicare assignment, the provider agrees to be paid directly by Medicare and to accept the payment amount approved by Medicare. Additionally, the provider agrees to not bill patients for more than the Medicare deductible and coinsurance amounts.
    A provider who doesn't accept assignment may charge you up to 15% over the Medicare-approved amount. This is known as the limiting charge. You may have to pay this amount, or it may be covered by another insurer.

  • Eligible to Order or Refer Part B Clinical Laboratory and Imaging: Yes

  • Eligible to Order or Refer Durable Medical Equipment (DMEPOS): Yes

  • Eligible to Order or Refer a Home Health Agency (HHA): Yes

  • Eligible to Order or Refer Power Mobility Devices: Yes

Provider Referred Orders for Durable Medical Equipment, Devices & Supplies

The following list reflects the services, supplies or durable medical equipment ordered by this provider to a DME supplier on behalf of patients. The information below is derived from Medicare claims data and reflects the BETOS category, HCPCS code information and the number times each service was submitted under the Medicare fee-for-service program.

Durable Medical Equipment

  • DME-Other DME (DE001N)

    Tubing with integrated heating element for use with positive airway pressure device (HCPCS:A4604)

    3 DME suppliers used 12 Medicare Claims 12 Services Paid

  • DME-Other DME (DE001N)

    Cushion for use on nasal mask interface, replacement only, each (HCPCS:A7032)

    2 DME suppliers used 11 Medicare Claims 41 Services Paid

  • DME-Other DME (DE001N)

    Filter, disposable, used with positive airway pressure device (HCPCS:A7038)

    3 DME suppliers used 12 Medicare Claims 72 Services Paid

  • DME-Other DME (DE001N)

    Continuous positive airway pressure (cpap) device (HCPCS:E0601)

    1 DME suppliers used 14 Medicare Claims 14 Services Paid

Areas of Expertise

The following services and procedures, recently provided to Medicare patients, illustrate the range of care this provider offers. This list reflects the variety of services available to all patients visiting the practice and is based on 2022 Medicare dataset. In general, the more frequently a provider treats specific conditions or performs particular procedures, the more experienced they become in addressing similar patient needs. The provider has delivered many of the services listed below to Medicare patients. Please note that this list does not include services provided to patients who are not covered by Medicare.

Blood test, clotting time

A clotting time blood test helps determine how quickly your blood forms clots, a process crucial to stop bleeding. During the test, a small blood sample is taken from your arm. The sample is then analyzed in a lab to see how long it takes for a clot to form.

This service was performed 307 times for 61 patients

Coronary angioplasty and stenting

Coronary angioplasty and stenting is a procedure to open narrowed or blocked heart arteries. A thin tube is inserted into a blood vessel, usually in the leg or arm, and guided to the heart. A small balloon at the end of the tube is inflated to widen the artery. A stent, a small wire mesh tube, may be placed in the artery to keep it open.

This service was performed for 23 patients

Established patient office or other outpatient visit, 10-19 minutes

This is a routine check-up for patients who have previously seen the doctor. During this 10-19 minute visit, the doctor will review your health status, discuss any concerns, and manage ongoing treatments or medications. It's a chance to ensure your health is on track.

This service was performed 30 times for 29 patients

Established patient office or other outpatient visit, 20-29 minutes

This is a routine visit for patients who have already been seen by the healthcare provider. During this approximately 20-29 minute appointment, your health status will be evaluated and any necessary treatments or tests will be discussed. It's a chance to address any health concerns you may have.

This service was performed 486 times for 314 patients

Established patient office or other outpatient visit, 30-39 minutes

This is a routine check-up for patients who have previously visited our clinic. It involves a comprehensive review of your health and any ongoing treatments. The consultation lasts between 30-39 minutes, allowing enough time to discuss any concerns.

This service was performed 223 times for 165 patients

Established patient office or other outpatient visit, 40-54 minutes

This service involves a follow-up appointment for existing patients, lasting between 40 to 54 minutes. During this time, your healthcare provider will assess your current health status, discuss any changes or concerns, review your treatment plan, and answer any questions you may have.

This service was performed 32 times for 32 patients

Exercise or drug-induced heart stress test with electrocardiogram (ecg) with supervision and review by physician

An exercise or drug-induced heart stress test with ECG is a procedure performed by a doctor to assess how your heart responds to exertion. It involves monitoring your heart's electrical activity while you exercise or after medication is given to mimic exercise effects.

This service was performed 17 times for 17 patients

Follow-up hospital inpatient care per day, typically 25 minutes

Follow-up hospital inpatient care involves daily check-ups while you're admitted in the hospital. Typically, a healthcare provider spends about 25 minutes each day reviewing your condition, adjusting treatment if needed, and answering any questions you might have.

This service was performed 94 times for 47 patients

Follow-up hospital inpatient care per day, typically 35 minutes

Follow-up hospital inpatient care per day typically involves a 35-minute check-up by your healthcare provider. This service includes monitoring your health progress, adjusting your treatment plan if needed, and answering any questions you may have about your condition or care.

This service was performed 31 times for 26 patients

Heart rhythm recording of continous external ekg over 8-15 days

A heart rhythm recording is a non-invasive procedure where a small device, attached externally, monitors your heart's electrical activity for 8-15 days. It helps detect irregular heart rhythms, assess heart rate, and guide treatment decisions. It's safe, painless, and can be done during normal daily activities.

This service was performed 12 times for 12 patients

Heart rhythm review and interpretation of continous external ekg over 8-15 days

This service involves wearing a device for 8-15 days that continuously records your heart's electrical activity. It helps in identifying irregular heart rhythms. The recorded data is then reviewed and interpreted by a healthcare professional for any abnormalities.

This service was performed 12 times for 12 patients

Initial hospital inpatient care per day, typically 30 minutes

Initial hospital inpatient care refers to the first day of your stay in the hospital. This service typically includes a 30-minute check-up with a healthcare professional. They'll assess your health, discuss your condition, and plan your treatment. It's part of ensuring you receive the best possible care.

This service was performed 22 times for 22 patients

Insertion of needle into vein for collection of blood sample

This procedure involves inserting a small needle into a vein, typically in your arm, to collect a blood sample. It's a quick and simple process to help diagnose or monitor health conditions. You may feel a small prick, but discomfort is minimal.

This service was performed 23 times for 15 patients

Insertion of tube in left lower heart chamber and coronary artery for diagnosis with review by radiologist

This procedure involves placing a tube into your left lower heart chamber and coronary artery. It helps doctors diagnose heart conditions by allowing them to view these areas in detail. A radiologist will review the images to ensure accurate diagnosis.

This service was performed 20 times for 20 patients

Leg revascularization (restoring blood flow)

Leg revascularization is a procedure aimed at restoring proper blood flow to your legs. It's often needed when blood vessels in your legs are blocked or narrowed. The process may involve surgery or less invasive methods to remove or bypass blockages, helping to alleviate pain and prevent serious complications.

This service was performed for 1-10 patients

New patient office or other outpatient visit, 45-59 minutes

This is a first-time office or outpatient visit lasting between 45-59 minutes. The healthcare provider evaluates your health, discusses your medical history, and may suggest further tests or treatments. It's an opportunity to ask questions and understand your health better.

This service was performed 15 times for 15 patients

Nuclear medicine studies of heart muscle at rest and with stress and spect

Nuclear medicine studies of the heart involve two parts: rest and stress. During rest, images are taken of your heart at ease. During stress, images are taken after exercise or medication-induced stress. SPECT is a special imaging technique providing 3D pictures of your heart, helping identify any issues.

This service was performed 19 times for 18 patients

Office or other outpatient visit for the evaluation and management of established patient that may not require presence of healthcare professional

This service involves an outpatient visit for established patients who may not need direct interaction with a healthcare professional. It could include reviewing test results, monitoring existing conditions, or adjusting treatment plans. It's typically done remotely, ensuring your comfort and convenience.

This service was performed 128 times for 39 patients

Pacemaker insertion or repair

Pacemaker insertion or repair is a procedure to help regulate your heartbeat. A small device, called a pacemaker, is implanted under the skin near your heart. This device sends electrical signals to prompt your heart to beat at a normal rate. In a repair procedure, the pacemaker may be adjusted, replaced, or the wires connecting it to your heart may be fixed.

This service was performed for 1-10 patients

Programming of dual lead pacemaker system

Programming of a dual lead pacemaker system is a procedure to adjust your heart's pacemaker settings. This process involves a small device, called a programmer, that communicates with your pacemaker to ensure it's working optimally for your heart's needs.

This service was performed 65 times for 41 patients

Programming of multiple lead implantable defibrillator system

Programming of a multiple lead implantable defibrillator system involves adjusting settings on your implanted device to help control irregular heart rhythms. The process is non-invasive and helps ensure optimal device performance for maintaining heart health.

This service was performed 29 times for 13 patients

Replacement of aortic valve through the skin and femoral artery

This procedure, known as Transcatheter Aortic Valve Replacement (TAVR), involves replacing a damaged aortic valve through a small incision in the leg. A catheter is inserted into the femoral artery and guided up to the heart. The new valve is then positioned and deployed, restoring normal blood flow.

This service was performed 24 times for 24 patients

Routine electrocardiogram (ecg) using at least 12 leads with interpretation and report

An electrocardiogram (ECG) is a non-invasive test that records your heart's electrical activity. Using 12 leads attached to your body, it captures data to help identify heart conditions. A doctor interprets the results and provides a report.

This service was performed 384 times for 266 patients

Routine electrocardiogram (ecg) using at least 12 leads with interpretation and report only

A routine electrocardiogram (ECG) with 12 leads is a simple, non-invasive test that records the electrical activity of your heart. It helps in identifying heart conditions by detecting irregularities in your heart rhythms. The results are interpreted and a report is provided.

This service was performed 791 times for 667 patients

Routine electrocardiogram (ecg) using at least 12 leads with tracing

An Electrocardiogram (ECG) is a simple, painless test that records the heart's electrical activity. Using 12 leads attached to your skin, it generates a tracing of your heart rhythm. It helps detect any heart problems by showing the timing and strength of electrical signals passing through each part of your heart.

This service was performed 21 times for 21 patients

Technetium tc-99m tetrofosmin, diagnostic, per study dose

Technetium Tc-99m Tetrofosmin is a radiopharmaceutical used in diagnostic imaging. It helps highlight areas of concern in the heart by emitting signals captured by a special camera. This assists doctors in detecting heart conditions.

This service was performed 34 times for 17 patients

Ultrasound of heart with color-depicted blood flow, rate, direction and valve function

This is a heart ultrasound, also known as an echocardiogram. It uses sound waves to create pictures of your heart, showing how blood flows through it. The color depicts the blood flow's speed and direction. It also checks the heart's valves to ensure they're working properly.

This service was performed 188 times for 187 patients

Ultrasound of heart with color-depicted blood flow, rate, direction and valve function

This is a heart ultrasound, also known as an echocardiogram. It uses sound waves to create pictures of your heart, showing how blood flows through it. The color depicts the blood flow's speed and direction. It also checks the heart's valves to ensure they're working properly.

This service was performed 221 times for 212 patients

Physician Visit Costs



The typical physician office visit costs for Medicare beneficiaries in this area are: $35.59 for a new patient copayment and $27.49 for an established patient copayment.

The pricing information below displays the copayment minimum, maximum and average amount that patients under Medicare are charged when visiting this provider as a new or established patient. Please keep in mind that these prices are just for reference purposes, and the actual prices charged by the provider might be different.

For patients covered under private health plans the prices below are also useful as healthcare pricing for private insurance is usually established as a function of Medicare prices. Private insurance covered patients should check their individual plans to determine the exact pricing.

The prices below reflect the costs for new and established patients in the 92835 ZIP code area.

New Patients Visit Costs *

The most utilized procedure code for new patients office visits is 99204

  • Average New Patient Price $142.39
  • Minimum New Patient Price $62.96
  • Maximum New Patient Price $187.6
  • Average New Patient Copayment $35.59
  • Minimum New Patient Copayment $15.74
  • Maximum New Patient Copayment $46.9

Established Patients Visit Costs *

The most utilized procedure code for established patients office visits is 99214

  • Average Established Patient Price $109.96
  • Minimum Established Patient Price $20.84
  • Maximum Established Patient Price $153.61
  • Average Established Patient Copayment $27.49
  • Minimum Established Patient Copayment $5.21
  • Maximum Established Patient Copayment $38.4

* The physician office visit costs information is generated by statistical analysis of similar providers in the same geographical area. The pricing information above IS NOT the amount charged by this provider.

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NPI NPI Number Validation

How NPI Validation Works

The NPI validation process uses the ISO-standard Luhn algorithm, a mathematical "handshake", to ensure that a provider's 10-digit ID is authentic and free of common typing errors.

To verify the NPI 1104812643, we treat the final digit (3) as the Check Digit—the target answer we need to reach. The process begins by taking the first nine digits and adding a constant value of 24, which accounts for the "80840" prefix required for all U.S. health identifiers. We then double every other digit starting from the right and sum the individual digits of those results together. For this specific NPI, that total comes to 57. The final step is to find the difference between that total and the next multiple of ten (60 - 57 = 3).

Digit-by-digit view

Use the first nine digits for the calculation. Starting from the right, double every other digit. The last digit is the check digit and is not part of the calculation.

Pos 1
1
Doubled → 2
Pos 2
1
Unchanged
Pos 3
0
Doubled → 0
Pos 4
4
Unchanged
Pos 5
8
Doubled → 16 → 1 + 6
Pos 6
1
Unchanged
Pos 7
2
Doubled → 4
Pos 8
6
Unchanged
Pos 9
4
Doubled → 8
Check
3
Target digit
Regular digit Doubled digit Check digit

Step 1: Double every other digit from the right

Starting with the rightmost digit of the first nine digits, double every other value. If doubling creates a two-digit number, add those digits together.

1 → 2 0 → 0 8 → 16 → 7 2 → 4 4 → 8

Step 2: Add all digits plus the NPI constant

Add the transformed values, the unchanged digits, and the constant 24.

2 + 1 + 0 + 4 + 1 + 6 + 1 + 4 + 6 + 8 + 24 = 57

Step 3: Find the amount needed to reach the next multiple of 10

The next multiple of ten after 57 is 60. The difference is the calculated check digit.

60 - 57 = 3
This NPI is valid
The calculated check digit is 3, which matches the last digit of 1104812643.

Other Providers at the Same Location


The following 20 providers are registered at the same or a nearby location.

Chiropractor (Orthopedic)
100 E VALENCIA MESA DR, SUITE 105
FULLERTON, CA 92835
Obstetrics & Gynecology (Gynecology)
100 E VALENCIA MESA DR, SUITE #215
FULLERTON, CA 92835
Pediatrics
100 E VALENCIA MESA DR, #100
FULLERTON, CA 92835
Dentist (Orthodontics and Dentofacial Orthopedics)
100 E VALENCIA MESA DR, SUITE 209
FULLERTON, CA 92835
Dentist (Pediatric Dentistry)
100 E VALENCIA MESA DR, STE 102
FULLERTON, CA 92835
Dentist (Oral and Maxillofacial Surgery)
100 E VALENCIA MESA DR, STE 305
FULLERTON, CA 92835
Physician Assistant (Surgical)
100 E VALENCIA MESA DR, SUITE 311
FULLERTON, CA 92835
Pharmacy (Community/Retail Pharmacy)
100 E VALENCIA MESA DR, SUITE 106
FULLERTON, CA 92835
Physician Assistant
100 E VALENCIA MESA DR, SUITE 310
FULLERTON, CA 92835
Pain Medicine (Interventional Pain Medicine)
100 E VALENCIA MESA DR, SUITE 310
FULLERTON, CA 92835
Chiropractor (Occupational Health)
100 E VALENCIA MESA DR, SUITE 105
FULLERTON, CA 92835
Obstetrics & Gynecology (Gynecology)
100 E VALENCIA MESA DR, SUITE # 215
FULLERTON, CA 92835
Internal Medicine (Endocrinology, Diabetes & Metabolism)
100 E VALENCIA MESA DR, SUITE 105
FULLERTON, CA 92835
Internal Medicine (Cardiovascular Disease)
100 E VALENCIA MESA DR, SUITE 206
FULLERTON, CA 92835
Pain Medicine (Pain Medicine)
100 E VALENCIA MESA DR, SUITE 310
FULLERTON, CA 92835
Specialist
100 E VALENCIA MESA DR, # 215
FULLERTON, CA 92835
Preferred Provider Organization
100 E VALENCIA MESA DR, STE. 100
FULLERTON, CA 92835
Obstetrics & Gynecology (Gynecology)
100 E VALENCIA MESA DR, #215
FULLERTON, CA 92835
Dentist (Endodontics)
100 E VALENCIA MESA DR, SUITE 306
FULLERTON, CA 92835
Pharmacy (Community/Retail Pharmacy)
100 E VALENCIA MESA DR
FULLERTON, CA 92835

Frequently Asked Questions

The NPI number assigned to this healthcare provider is 1104812643, enumerated as an "individual" on September 20, 2005.

The provider is located at 100 E VALENCIA MESA DR SUITE 206 FULLERTON, CA 92835 and the phone number is (714) 446-5050.

Internal Medicine with taxonomy code 207RI0011X and a focus in Interventional Cardiology.