Quick answers
- Which hospitals does Ronald T. Grenko work at?
- Medicare's official clinician data lists Ronald T. Grenko at 1 hospital: Lancaster General Hospital. This is where the clinician works or has privileges; call the hospital to confirm.
- Where does Ronald T. Grenko see patients?
- Medicare's clinician data lists 1 practice location in Lancaster, PA. Call before your visit to confirm the address.
- What is Ronald T. Grenko's specialty?
- Medicare lists Pathology as the primary specialty.
- Does Ronald T. Grenko accept Medicare assignment?
- Yes. Medicare's clinician data says Ronald T. Grenko 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 Ronald T. Grenko?
- (717) 544-5511, as listed in official Medicare / NPI Registry data.
- What is Ronald T. Grenko's NPI number?
- 1861454571. The NPI (National Provider Identifier) is the clinician's permanent federal ID; you can look it up in the official NPI Registry.
Hospitals where Ronald T. Grenko works
Medicare's Facility Affiliation Data lists Ronald T. Grenko at these hospitals (updated 2026-10-02). Each hospital page shows its address, phone, emergency services, Medicare rating and all its clinicians.
- Lancaster General HospitalLancaster, PA · Acute Care Hospital · CCN 390100
Practice locations
Addresses where Ronald T. Grenko is enrolled with Medicare (CMS data updated 2026-10-02).
- 555 N Duke St, Penn Medicine Lancaster General Health PathLancaster, PA 17602 (717) 544‑5511
Group practices
Medicare enrollment lists Ronald T. Grenko as a member of this group (CMS data updated 2026-10-02).
- Lancaster General Hospital520 clinicians in the group
Specialties
- Pathologyprimary
Other pathologists in Lancaster
Clinicians with the same Medicare primary specialty in Lancaster, PA — not a recommendation.
Clinician information
| Credential | MD |
|---|---|
| Medical school | University Of Cincinnati College Of Medicine |
| Graduation year | 1985 |
| Gender (as listed) | Male |
| Medicare assignment | Accepts (Medicare-approved amount as full payment) |
| NPI (National Provider Identifier) | 1861454571 |
| 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