Quick answers
- Which hospitals does Timothy Harrison work at?
- Medicare's official clinician data lists Timothy Harrison at 1 hospital: St Catherine of Siena Hospital. This is where the clinician works or has privileges; call the hospital to confirm.
- Where does Timothy Harrison see patients?
- Medicare's clinician data lists 1 practice location in Mount Kisco, NY. Call before your visit to confirm the address.
- What is Timothy Harrison's specialty?
- Medicare lists Ophthalmology as the primary specialty.
- Does Timothy Harrison accept Medicare assignment?
- Yes. Medicare's clinician data says Timothy Harrison 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 Timothy Harrison?
- (914) 241-1050, as listed in official Medicare / NPI Registry data.
- What is Timothy Harrison's NPI number?
- 1811991300. The NPI (National Provider Identifier) is the clinician's permanent federal ID; you can look it up in the official NPI Registry.
Hospitals where Timothy Harrison works
Medicare's Facility Affiliation Data lists Timothy Harrison at these hospitals (updated 2026-10-02). Each hospital page shows its address, phone, emergency services, Medicare rating and all its clinicians.
- St Catherine of Siena HospitalSmithtown, NY · Acute Care Hospital · CCN 330401
Practice locations
Addresses where Timothy Harrison is enrolled with Medicare (CMS data updated 2026-10-02).
- 90 S Bedford RdMount Kisco, NY 10549 (914) 241‑1050
Group practices
Medicare enrollment lists Timothy Harrison as a member of this group (CMS data updated 2026-10-02).
- Optum Medical Care PC1,010 clinicians in the group
Specialties
- Ophthalmologyprimary
Other ophthalmologists in Mount Kisco
Clinicians with the same Medicare primary specialty in Mount Kisco, NY — not a recommendation.
Clinician information
| Credential | MD |
|---|---|
| Graduation year | 2000 |
| Gender (as listed) | Male |
| Medicare assignment | Accepts (Medicare-approved amount as full payment) |
| NPI (National Provider Identifier) | 1811991300 |
| 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
- Facility Affiliation Data — Centers for Medicare & Medicaid Services (CMS), data updated 2026-10-02, retrieved 2026-10-29
- 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