Quick answers
- Where does John C. Frederick see patients?
- Medicare's clinician data lists 3 practice locations, including Geneseo, IL, Rock Island, IL and Bettendorf, IA. Call before your visit to confirm the address.
- What is John C. Frederick's specialty?
- Medicare lists Ophthalmology as the primary specialty.
- Does John C. Frederick accept Medicare assignment?
- Yes. Medicare's clinician data says John C. Frederick 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 John C. Frederick?
- (309) 944-8888, as listed in official Medicare / NPI Registry data.
- What is John C. Frederick's NPI number?
- 1043297492. 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 John C. Frederick is enrolled with Medicare (CMS data updated 2026-10-02).
- 422 S State StGeneseo, IL 61254 (309) 944‑8888
- 4731 45th St CtRock Island, IL 61201 (309) 793‑2020
- 777 Tanglefoot LnBettendorf, IA 52722 (563) 323‑2020
Group practices
Medicare enrollment lists John C. Frederick as a member of this group (CMS data updated 2026-10-02).
- Eye Surgeons Associates PC20 clinicians in the group
Specialties
- Ophthalmologyprimary
Other ophthalmologists in Geneseo
Clinicians with the same Medicare primary specialty in Geneseo, IL — not a recommendation.
Clinician information
| Credential | MD |
|---|---|
| Medical school | University Of Iowa, Rj & L Carver College Of Medicine |
| Graduation year | 1993 |
| Gender (as listed) | Male |
| Medicare assignment | Accepts (Medicare-approved amount as full payment) |
| NPI (National Provider Identifier) | 1043297492 |
| Corrections | Report 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
- National Downloadable File (Doctors and Clinicians) — CMS, data updated 2026-10-02, retrieved 2026-10-29
- NPI Registry — U.S. Department of Health and Human Services (NPPES), the clinician’s official record
- Medicare Care Compare — official Medicare tool to look up clinicians