Doctor profile · Federal record

Dr. Sang Hoon Ahn, M.D.

Internal Medicine Physician (CMS: Hematology/Oncology) · Medical Oncology Physician · Fullerton, CA

  • NPI 1568581759
  • Accepts Medicare
  • 32 yrs in practice
  • Male
  • Solo practice
  • No sanctions

Practice & contact

Operates at 3 locations .

NPPES Updated May 11, 2026
Primary practice
1950 Sunny Crest Dr Ste 2800
Fullerton, CA 928353641
(657) 888-9919
fax (657) 888-9941
Additional location
500 S Virgil Ave, Suite 502
Los Angeles, CA 900201446
(213) 388-0908
fax (213) 388-0919
Additional location
5832 Beach Blvd Unit 201
Buena Park, CA 906215501
(714) 522-0908
fax (714) 522-0919
Mailing address
1520 Hollydale Dr
Fullerton, CA 928311115

Credentials & registration

NPPES · NUCC
NPI registered
March 2007 — 19 yrs on file
Profile last updated
February 18, 2026
Year of graduation
1994 — 32 yrs since
Specialty taxonomy
207R00000X — NUCC code
State license (1)
California #A95562
Medicaid
CA #00A955620

Federal sanctions & exclusions

OIG LEIE Updated May 11, 2026

No sanctions, exclusions or revocations on file

Checked against OIG LEIE on NPI 1568581759. Last verified May 11, 2026.

Medicare procedures · 2023

Top services delivered

CMS Provider Utilization
Total services
1,397
Distinct HCPCS
8
Medicare allowed
$132,632
HCPCS Description Services Patients Avg allowed
99214 Established patient office or other outpatient visit, 30-39 minutes 659 337 $104
99441 Telephone medical discussion with physician, 5-10 minutes 326 205 $37
99215 Established patient office or other outpatient visit, 40-54 minutes 151 98 $152
99205 New patient office or other outpatient visit, 60-74 minutes 68 68 $192
99204 New patient office or other outpatient visit, 45-59 minutes 62 62 $141
99212 Established patient office or other outpatient visit, 10-19 minutes 54 30 $38
99213 Established patient office or other outpatient visit, 20-29 minutes 47 42 $70
99442 Telephone medical discussion with physician, 11-20 minutes 30 27 $70

In context: peer comparison

Among 14 peers in this city , average services per provider: 146. This provider delivers 9.6× the peer median.

Open Payments

Industry payments received

CMS Open Payments
All-time total
$48
Transactions
3
Manufacturers
3
Payer (manufacturer) Industry Txns Amount
Merck Sharp & Dohme LLC 1 $18.09
Agios Pharmaceuticals, Inc. 1 $16.53
BeiGene USA, Inc. 1 $13.74

By nature of payment

Education
$35
Food and Beverage
$14

Medicare Part D · 2023

Top prescriptions

CMS Part D Prescriber
Total claims
741
Patients
98
Total drug cost
$5,013,435
Drug Type Claims Patients Total cost
Tagrisso (Osimertinib Mesylate) Brand 78 0 $1,344,000
Promacta (Eltrombopag Olamine) Brand 72 0 $708,115
Anastrozole Generic 70 23 $3,142
Procrit (Epoetin Alfa) Brand 65 26 $95,442
Letrozole Generic 61 21 $2,474
Abiraterone Acetate Generic 58 0 $88,935
Hydroxyurea Generic 51 17 $1,334
Tasigna (Nilotinib Hcl) Brand 46 0 $789,015
Prednisone Generic 42 0 $291
Levothyroxine Sodium Generic 39 11 $639

Frequently asked questions

Auto-generated from federal data
What is Dr. Sang Hoon Ahn's medical specialty?
Dr. Sang Hoon Ahn practices Internal Medicine Physician in Fullerton, CA.
Where does Dr. Sang Hoon Ahn practice?
Dr. Sang Hoon Ahn practices at 1950 Sunny Crest Dr Ste 2800, Fullerton, CA 928353641. Office phone: 6578889919.
What is Dr. Sang Hoon Ahn's NPI?
Dr. Sang Hoon Ahn's National Provider Identifier (NPI) is 1568581759, issued by NPPES.
Does Dr. Sang Hoon Ahn accept Medicare assignment?
Yes. Dr. Sang Hoon Ahn accepts Medicare assignment, meaning Medicare-allowed amounts are accepted as full payment for covered services.
What procedures does Dr. Sang Hoon Ahn commonly perform?
Top Medicare-reported procedures in 2023: Established patient office or other outpatient visit (HCPCS 99214); Telephone medical discussion with physician (HCPCS 99441); Established patient office or other outpatient visit (HCPCS 99215). Source: CMS Medicare Physician & Other Practitioners file.