James Ahn, M.D.
NPI 1902915028 · Ophthalmology Physician · Palo Alto, CA
Enrolled with Medicare as Practitioner - Ophthalmology · source: CMS PECOS Public Provider Enrollment (2026.04.01)
James Ahn, M.D. is a Ophthalmology Physician provider in Palo Alto, CA (NPI 1902915028).
Provider details
- NPI number
- 1902915028
- Entity type
- Individual
- Primary specialty
- Ophthalmology PhysicianAllopathic & Osteopathic Physicians
- Credential
- M.D.
- Sex
- Male
- Sole proprietor
- No
- License
- G52250 (CA)
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
19 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
212 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) |
|---|---|---|
| Established Patient Office Or Other Outpatient Visit With Moderate Level of Decision Making, If Using Time, 30 Minutes Or More99214 | 85 | $156 |
| Imaging of Optic Nerve92133 | 40 | $45 |
| Exam to Measure Eye Deviation and Range of Motion92060 | 26 | $82 |
| Established Patient Office Or Other Outpatient Visit With High Level of Medical Decision Making, If Using Time, 40 Minutes Or More99215 | 23 | $217 |
| Established Patient Office Or Other Outpatient Visit With Low Level OD Decision Making, If Using Time, 20 Minutes Or More99213 | 22 | $111 |
| Exam of Visual Field With Extended Testing92083 | 16 |
What this provider prescribes (Medicare Part D)
Top drugs by Medicare Part D claim volume, 2024 · 1 distinct drug on file.
| Drug | Part D claims (2024) |
|---|---|
| Latanoprost | 15 |
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
- 2006-08-30
- Last updated
- 2020-03-03
- Certified
- 2020-03-03
Frequently asked questions
- What is James Ahn's NPI number?
- James Ahn's National Provider Identifier (NPI) is 1902915028, a unique 10-digit ID issued by CMS for use in standard healthcare transactions.
- What is James Ahn's specialty?
- James Ahn is listed in the NPPES registry with a primary specialty of Ophthalmology Physician (Allopathic & Osteopathic Physicians).
- Where is James Ahn located?
- James Ahn's practice location on file with NPPES is 795 El Camino Real, Palo Alto, CA 94301-2302.
- What is James Ahn's phone number?
- The practice phone number listed in the NPPES registry for James Ahn is (650) 321-4121.
- Does James Ahn accept Medicare?
- James Ahn is approved to bill Medicare according to CMS PECOS enrollment data (2026.04.01). Confirm current participation with the provider before scheduling.
- Is James Ahn's NPI active?
- Yes — James Ahn's NPI (1902915028) is active in the NPPES registry as of the last update on 2020-03-03.
Source: CMS NPPES Data Dissemination (June 2026). NPI Central is not affiliated with CMS. Data is provided as-is from the public registry.