Sang Hoon Ahn, M.D.
NPI 1568581759 · Internal Medicine Physician · Fullerton, CA
Enrolled with Medicare as Practitioner - Hematology/Oncology · source: CMS PECOS Public Provider Enrollment (2026.04.01)
Sang Hoon Ahn, M.D. is a Internal Medicine Physician provider in Fullerton, CA (NPI 1568581759).
Provider details
- NPI number
- 1568581759
- Entity type
- Individual
- Primary specialty
- Internal Medicine PhysicianAllopathic & Osteopathic Physicians
- Credential
- M.D.
- Sex
- Male
- Sole proprietor
- Yes
- License
- A95562 (CA)
Specialties & taxonomies
Allopathic & Osteopathic Physicians
Allopathic & Osteopathic Physicians
Profile Score
A profile completeness & documented-activity index — NOT a quality, outcomes, or patient-satisfaction rating.
- Registry tenure25% of score
19 yrs in NPPES registry
- Profile completeness25% of score
100% of core fields populated
- Practice footprint15% of score
3 documented practice locations
- Medicare service volume (vs. specialty peers)25% of score
1,309 Medicare services, 2024 (ranked within specialty)
- Open Payments transparency10% of score
Has Open Payments disclosures (2024)
Medicare volume is ranked against active providers in the same specialty. Signals a provider has no public data for (e.g. Medicare claims) are left out of the score entirely — never counted as zero — so providers without that data are not penalized. See the full formula and weights in our .
What this provider does (Medicare)
Based on Medicare fee-for-service claims, 2024; not all care is captured.
| Service (HCPCS) | Medicare services | Typical Medicare-allowed (2024) |
|---|---|---|
| Established Patient Office Or Other Outpatient Visit With Moderate Level of Decision Making, If Using Time, 30 Minutes Or More99214 | 686 | $102 |
| Telephone Medical Discussion With Physician, 5-10 Minutes99441 | 217 | $38 |
| Established Patient Office Or Other Outpatient Visit With Low Level OD Decision Making, If Using Time, 20 Minutes Or More99213 | 154 | $69 |
| Established Patient Office Or Other Outpatient Visit With High Level of Medical Decision Making, If Using Time, 40 Minutes Or More99215 | 69 | $151 |
| New Patient Office Or Other Outpatient Visit With Moderate Level of Medical Decision Making, If Using Time, 45 Minutes Or More99204 | 66 | $139 |
| New Patient Office Or Other Outpatient Visit With a High Level of Medical Decision Making, If Using Time, 60 Minutes Or More |
What this provider prescribes (Medicare Part D)
Top drugs by Medicare Part D claim volume, 2024 · 29 distinct drugs on file.
| Drug | Part D claims (2024) | Beneficiaries |
|---|---|---|
| Anastrozole | 83 | 20 |
| Letrozole | 83 | 24 |
| Eltrombopag Olaminebrand: Promacta | 78 | — |
| Osimertinib Mesylatebrand: Tagrisso | 75 | — |
| Abiraterone Acetate | 53 | — |
| Apalutamidebrand: Erleada | 53 | — |
| Lenalidomidebrand: Revlimid | 46 | — |
Transparency — industry payments
Based on CMS Open Payments, 2024; not all care is captured.
$48 across 3 records (Open Payments 2024)
Open Payments discloses payments and transfers of value (meals, travel, consulting, research, royalties) from drug and device makers to providers. This is a transparency signal, not a verdict — such payments are legal and common, and their presence is neither an endorsement nor a criticism. Source: CMS Open Payments, program year 2024.
Practice location
Mailing address
Additional practice locations (2)
- 5832 Beach Blvd Unit 201Buena Park, CA 90621-5501Phone: (714) 522-0908Fax: (714) 522-0919
- 500 S Virgil AveSuite 502Los Angeles, CA 90020-1446Phone: (213) 388-0908Fax: (213) 388-0919
Registry dates
- Enumerated
- 2007-03-28
- Last updated
- 2026-02-18
- Certified
- 2026-02-18
Frequently asked questions
- What is Sang Hoon Ahn's NPI number?
- Sang Hoon Ahn's National Provider Identifier (NPI) is 1568581759, a unique 10-digit ID issued by CMS for use in standard healthcare transactions.
- What is Sang Hoon Ahn's specialty?
- Sang Hoon Ahn is listed in the NPPES registry with a primary specialty of Internal Medicine Physician (Allopathic & Osteopathic Physicians).
- Where is Sang Hoon Ahn located?
- Sang Hoon Ahn's practice location on file with NPPES is 1950 Sunny Crest Dr Ste 2800, Fullerton, CA 92835-3641.
- What is Sang Hoon Ahn's phone number?
- The practice phone number listed in the NPPES registry for Sang Hoon Ahn is (657) 888-9919.
- Does Sang Hoon Ahn accept Medicare?
- Sang Hoon Ahn is approved to bill Medicare according to CMS PECOS enrollment data (2026.04.01). Confirm current participation with the provider before scheduling.
- Is Sang Hoon Ahn's NPI active?
- Yes — Sang Hoon Ahn's NPI (1568581759) is active in the NPPES registry as of the last update on 2026-02-18.
Source: CMS NPPES Data Dissemination (June 2026). NPI Central is not affiliated with CMS. Data is provided as-is from the public registry.