Provider records sourced from NPPES (CMS National Plan & Provider Enumeration System). Data current as of October 4, 2026.
NPIDirectory

John K Derderian, DO

Individual provider Internal Medicine Physician · NPI 1477595445

John K Derderian, DO practises Internal Medicine in Lancaster, Pennsylvania. Graduated from Philadelphia College of Osteopathic Medicine in 2000, 26 years ago. Practices with Lancaster General Hospital, a 518-clinician group and accepts Medicare assignment. Licensed in Pennsylvania.

Years since qualifying
26
Trained at
Philadelphia College of Osteopathic Medicine
Licensed in
PA
In the registry since
2006
What do these letters mean?
DO — Doctor of Osteopathic Medicine
A fully licensed physician, trained like an MD with additional musculoskeletal training. Equivalent practice rights in all 50 states.

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Practice location Address checks out

555 N Duke St
Lancaster, PA 17602-2250
Phone: (717) 544-5511
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Pin is approximate — placed at the ZIP-code centre, not the exact door.

Specialties & licences

Internal Medicine Physician (primary) Taxonomy 207R00000X · Licence OS011857 (PA)

Record details

NPI number1477595445
Entity typeIndividual (Type 1)
GenderMale
Credentials DO
Sole proprietorNo
NPI enumeratedJune 12, 2006
Last updated in NPPESNovember 1, 2025
Certification dateNovember 1, 2025

Medicare enrollment

From the CMS Doctors & Clinicians file — this clinician is enrolled in Medicare.

Medicare specialtyINTERNAL MEDICINE
Medical schoolPHILADELPHIA COLLEGE OF OSTEOPATHIC MEDICINE
Graduated 2000 (26 years in practice)
Group practice Lancaster General Hospital — 518 clinicians
Accepts Medicare assignment Yes — accepts the Medicare-approved amount
Practice locations2 on file with Medicare

Payments from drug and device companies, 2025

Drug and device makers are required by federal law (the Physician Payments Sunshine Act) to report what they pay or give to clinicians, and CMS publishes the reports as Open Payments. This is the 2025 program year. A report is a record of a payment, not an allegation of anything, and many are small items such as meals. Only general payments are listed here; research payments and ownership or investment interests are reported separately by CMS and are not shown.

Food and Beverage $31 1 payment · a meal or drink at a meeting or visit, not a fee

Each amount is the sum of what companies reported for that kind of payment in 2025, rounded to the dollar. Not all of it is income to the clinician: a meal is not a fee, a charitable contribution goes to a charity, and a royalty or an acquisition payment is not a salary.

Check a report, or dispute one, at the source in CMS’s own tool, Open Payments. Corrections go through CMS’s dispute process. This site removes a home address on request and asks for no proof, because that is privacy; it will not remove an accurate payment report on request, because that is a statutory public disclosure.

Practises at

Facilities the CMS Facility Affiliation file lists for this clinician.

Colleagues at Lancaster General Hospital

Clinicians the CMS Doctors & Clinicians file lists under the same group practice. CMS counts 518 clinicians in the practice; 12 are shown here.

Other providers in Lancaster