Ji Won Ahn, MD
NPI 1023460243 · MOHS-Micrographic Surgery Physician · Walnut Creek, CA
Enrolled with Medicare as Practitioner - Dermatology · source: CMS PECOS Public Provider Enrollment (2026.04.01)
Ji Won Ahn, MD is a MOHS-Micrographic Surgery Physician provider in Walnut Creek, CA (NPI 1023460243).
Provider details
- NPI number
- 1023460243
- Entity type
- Individual
- Primary specialty
- MOHS-Micrographic Surgery PhysicianAllopathic & Osteopathic Physicians
- Credential
- MD
- Sex
- Female
- Sole proprietor
- No
- License
- 66941 (MN)
Specialties & taxonomies
Allopathic & Osteopathic Physicians
Profile Score
A profile completeness & documented-activity index — NOT a quality, outcomes, or patient-satisfaction rating.
- Registry tenure28% of score
9 yrs in NPPES registry
- Profile completeness28% of score
100% of core fields populated
- Practice footprint17% of score
1 documented practice location
- Medicare service volume (vs. specialty peers)28% of score
244 Medicare services, 2024 (ranked within specialty)
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 methodology.
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) |
|---|---|---|
| Destruction of Precancer Skin Growth, 2-14 Growths17003 | 78 | $5 |
| Established Patient Office Or Other Outpatient Visit With Low Level OD Decision Making, If Using Time, 20 Minutes Or More99213 | 37 | $82 |
| Biopsy of Related Skin Growth, First Growth11102 | 33 | $70 |
| Destruction of Precancer Skin Growth, 1 Growth17000 | 30 | $44 |
| Removal and Microscopic Exam of Growth of Head, Neck, Hands, Feet, Or Genitals, 1-5 Tissue Blocks17311 | 25 | $441 |
| Biopsy of Related Skin Growth, Each Additional Growth |
What this provider prescribes (Medicare Part D)
Top drugs by Medicare Part D claim volume, 2024 · 5 distinct drugs on file.
| Drug | Part D claims (2024) | Beneficiaries |
|---|---|---|
| Mupirocin | 72 | 58 |
| Cefadroxil | 64 | 55 |
| Doxycycline Hyclate | 21 | 20 |
| Tramadol Hcl | 12 | — |
| Fluorouracil | 11 | — |
Medicare Part D only. These counts cover prescriptions paid through Medicare Part D in 2024 — they do notinclude cash-pay, commercial-insurance, Medicaid, or Part B–administered drugs, and badly undercount high cash-pay categories (e.g. GLP-1 weight-loss, testosterone, and ED medications). Any drug with 10 or fewer claims is omitted by CMS, and beneficiary counts under 11 are suppressed — so a missing drug means no Part D record, never zero. This is a factual claims summary, not an endorsement, not medical advice, and not a consumer report. Source: CMS Medicare Part D Prescribers — by Provider and Drug.
Practice location
Mailing address
Registry dates
- Enumerated
- 2016-07-12
- Last updated
- 2024-10-30
- Certified
- 2024-10-30
Frequently asked questions
- What is Ji Won Ahn's NPI number?
- Ji Won Ahn's National Provider Identifier (NPI) is 1023460243, a unique 10-digit ID issued by CMS for use in standard healthcare transactions.
- What is Ji Won Ahn's specialty?
- Ji Won Ahn is listed in the NPPES registry with a primary specialty of MOHS-Micrographic Surgery Physician (Allopathic & Osteopathic Physicians).
- Where is Ji Won Ahn located?
- Ji Won Ahn's practice location on file with NPPES is 320 Lennon Ln Dept of, Walnut Creek, CA 94598-2419.
- What is Ji Won Ahn's phone number?
- The practice phone number listed in the NPPES registry for Ji Won Ahn is (925) 817-5678.
- Does Ji Won Ahn accept Medicare?
- Ji Won Ahn is approved to bill Medicare according to CMS PECOS enrollment data (2026.04.01). Confirm current participation with the provider before scheduling.
- Is Ji Won Ahn's NPI active?
- Yes — Ji Won Ahn's NPI (1023460243) is active in the NPPES registry as of the last update on 2024-10-30.
Source: CMS NPPES Data Dissemination (June 2026). NPI Central is not affiliated with CMS. Data is provided as-is from the public registry.