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Ophthalmology

James C. Ahn, MD

Sees patients in Palo Alto, CA · California

Summary

James C. Ahn, MD (Ophthalmology) is enrolled with Medicare at 1 practice location in Palo Alto, CA. NPI 1902915028. Medicare data says the clinician accepts Medicare assignment. Source: CMS National Downloadable File, updated 2026-10-02.

From official Medicare data

This page shows what Medicare's official clinician data says about James C. Ahn, joined by NPI number (data updated 2026-10-02). It is not a recommendation or a rating. Call the office or hospital to confirm before you go.

In a medical emergency, call 911.

At a glance

OphthalmologyPrimary specialty
YesAccepts Medicare assignment
44Years since medical school (graduated 1982)
Boston University School Of MedicineMedical school
MaleGender (as listed)
Sutter Bay Medical FoundationGroup practice

Quick answers

Where does James C. Ahn see patients?
Medicare's clinician data lists 1 practice location in Palo Alto, CA. Call before your visit to confirm the address.
What is James C. Ahn's specialty?
Medicare lists Ophthalmology as the primary specialty.
Does James C. Ahn accept Medicare assignment?
Yes. Medicare's clinician data says James C. Ahn accepts Medicare assignment (the Medicare-approved amount as full payment for covered services), as of 2026-10-02. Ask the office to confirm before your visit.
What is the phone number for James C. Ahn?
(415) 600-1020, as listed in official Medicare / NPI Registry data.
What is James C. Ahn's NPI number?
1902915028. The NPI (National Provider Identifier) is the clinician's permanent federal ID; you can look it up in the official NPI Registry.

Practice locations

Addresses where James C. Ahn is enrolled with Medicare (CMS data updated 2026-10-02).

Group practices

Medicare enrollment lists James C. Ahn as a member of this group (CMS data updated 2026-10-02).

  • Sutter Bay Medical Foundation3,829 clinicians in the group

Specialties

Find other Ophthalmology doctors in California →

Other ophthalmologists in Palo Alto

Clinicians with the same Medicare primary specialty in Palo Alto, CA — not a recommendation.

All ophthalmologists in Palo Alto →

Clinician information

CredentialMD
Medical schoolBoston University School Of Medicine
Graduation year1982
Gender (as listed)Male
Medicare assignmentAccepts (Medicare-approved amount as full payment)
NPI (National Provider Identifier)1902915028
CorrectionsReport an error or suggest an update →

Most corrections must be made at the source: clinicians update their NPI Registry record (NPPES) and their Medicare enrollment (PECOS); this page follows the next data release.

Sources

  1. National Downloadable File (Doctors and Clinicians) — CMS, data updated 2026-10-02, retrieved 2026-10-29
  2. NPI Registry — U.S. Department of Health and Human Services (NPPES), the clinician’s official record
  3. Medicare Care Compare — official Medicare tool to look up clinicians