1. Home
  2. Directory
  3. California
  4. Irvine
  5. Internal Medicine
  6. NPI Profile

DR. KAREN SUN M.D.
NPI 1326229220
Internal Medicine in Irvine, CA

Active since November 19, 2007Opted out of Medicare · through Oct 1, 2026
4 HUGHES STE 150, IRVINE, CA 92618(949) 768-6780(949) 768-6782 Get Directions Write a Review

NPPES record last updated: November 19, 2007. Verified against the NPPES registry weekly; last sync: August 09, 2026.

About Dr. Karen Sun M.d. NPPES

Official registry information on file with the National Plan and Provider Enumeration System.

DR. KAREN SUN M.D. (NPI 1326229220) is an individual internal medicine provider in Irvine, California, licensed in California (A41436) and active in the NPI registry since November 2007. She has opted out of Medicare through October 1, 2026 and remains eligible to order and refer.

NPPES Registry Identity

NPI1326229220
Entity TypeIndividualFemale
Primary Taxonomy207R00000X
Provider Legal NameDR. KAREN SUNCredential: M.D.
Location Address4 HUGHES STE 150Irvine, CA 92618-2044
Mailing Address4 Hughes Ste 150Irvine, CA 92618-2044 · (949) 768-6780 · Fax (949) 768-6782
Phone(949) 768-6780
Fax(949) 768-6782
Sole ProprietorNo
Enumeration DateNovember 19, 2007
✔ NPI 1326229220 is a valid, active identifier and passes the ISO check-digit test.

Specialties & Licenses

★ Primary SpecialtyInternal MedicineAllopathic & Osteopathic Physicians
Taxonomy Code207R00000X
License✔ Licensed in CA · A41436
Definition
A physician who provides long-term, comprehensive care in the office and the hospital, managing both common and complex illness of adolescents, adults and the elderly. Internists are trained in the diagnosis and treatment of cancer, infections and diseases affecting the heart, blood, kidneys, joints and digestive, respiratory and vascular systems. They are also trained in the essentials of primary care internal medicine, which incorporates an understanding of disease prevention, wellness, substance abuse, mental health and effective treatment of common problems of the eyes, ears, skin, nervous system and reproductive organs.
4 HUGHES STE 150, Irvine, CA 92618
Open in Google Maps ↗

Other Identifiers 1

Medicare UPINA29377CA

Medicare Participation & PECOS CMS

Medicare enrollment, assignment, and ordering and referring status from the CMS PECOS system.

Medicare Enrollment Status

ⓘ

Opted out of Medicare

Dr. Karen Sun M.d. has filed a Medicare opt-out affidavit. Services are provided under private contract between the provider and the patient, and are not billed to or reimbursed by Medicare. The opt-out is on file from October 1, 2018 through October 1, 2026.

Opt-Out Effective DateOctober 1, 2018
Opt-Out In Effect ThroughOctober 1, 2026Opt-out affidavits renew automatically every two years unless cancelled
Eligible to Order & Refer✔ Part B Labs & Imaging✔ Durable Medical Equipment✔ Home Health Agency✔ Power Mobility DevicesAn opted-out provider can still order and refer for Medicare patients in the categories marked above, even though their own services are not covered.

Physician Visit Costs CMS claims · ZIP area

Typical Medicare office-visit costs in the 92618 ZIP code area, from fee-for-service claims. These are area statistics, not this provider’s prices; actual charges vary by service and coverage.

New Patient
$142.39 typical visit price
range $62.96 – $187.60
Typical copayment $35.59 (range $15.74 – $46.90)
Most-billed visit code 99204
Established Patient
$109.96 typical visit price
range $20.84 – $153.61
Typical copayment $27.49 (range $5.21 – $38.40)
Most-billed visit code 99214
Amounts reflect what Medicare beneficiaries in this ZIP area are typically charged for office visits. Patients with other coverage should check their individual plans.

Other Providers at the Same Location NPPES 2

Providers registered at the same practice address, or within the immediate area, according to the NPPES registry.

ANNIE TAK
Nurse Practitioner (Family)
4 HUGHES STE 150
IRVINE, CA 92618
Orange County (949) 768-6780
KAREN SUN,M.D, INC
Clinic/Center
4 HUGHES STE 150
IRVINE, CA 92618
Orange County (949) 768-6782

Frequently Asked Questions NPPES & CMS

Common questions about this NPI record, answered from the official NPPES registry and CMS datasets shown on this page.

What is Karen Sun's NPI number?

The NPI number for Karen Sun is 1326229220. It was assigned to this individual provider in the NPPES registry on November 19, 2007.

Where is Karen Sun located?

Karen Sun practices at 4 Hughes Ste 150, Irvine, CA 92618. The listed phone number is (949) 768-6780.

What is Karen Sun's specialty?

The primary specialty registered for this NPI is Internal Medicine with taxonomy code 207R00000X.

Is Karen Sun enrolled in Medicare?

No. Karen Sun has opted out of Medicare through October 1, 2026. Care is provided under private contracts, and Medicare does not pay for services furnished by providers who have opted out. The provider remains eligible to order and refer services for Medicare patients.

When was this NPI record last updated?

The NPPES record for Karen Sun was last updated on November 19, 2007. NPI Profile syncs weekly with the NPPES registry data releases published by CMS. This NPI record was last updated 18 years ago. If this record has changed at CMS more recently, you can request an on-demand re-check against the live CMS registry, directly from this page.