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

Frederick Sebastian Fleszler, MD

Individual provider Nephrology Physician · NPI 1588758353

Frederick Sebastian Fleszler, MD practises Nephrology in Allentown, Pennsylvania. Qualified in 1999, 27 years ago. Practices with Valley Kidney Specialists, PC, a 31-clinician group, accepts Medicare assignment and offers telehealth. Licensed in New Jersey and Pennsylvania.

Years since qualifying
27
Licensed in
NJ, PA
In the registry since
2006
Specialties on file
2
What do these letters mean?
MD — Doctor of Medicine
A physician who completed allopathic medical school.

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Practice location Address checks out

1230 S Cedar Crest Blvd Stes 301 302 304
Allentown, PA 18103-6212
Phone: (610) 432-4529
Fax: (610) 432-2206
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Pin is approximate — placed at the ZIP-code centre, not the exact door.

Specialties & licences

Nephrology Physician (primary) Taxonomy 207RN0300X · Licence MD428393 (PA)
Nephrology Physician Taxonomy 207RN0300X · Licence 25MA08358900 (NJ)

Record details

NPI number1588758353
Entity typeIndividual (Type 1)
GenderMale
Credentials MD
Sole proprietorNo
NPI enumeratedOctober 3, 2006
Last updated in NPPESMay 31, 2022
Certification dateMay 31, 2022

Medicare enrollment

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

Medicare specialtyNEPHROLOGY
Also practisesINTERNAL MEDICINE
Medical schoolOTHER
Graduated 1999 (27 years in practice)
Group practice Valley Kidney Specialists, P.C. — 31 clinicians
Accepts Medicare assignment Yes — accepts the Medicare-approved amount
TelehealthOffers telehealth services

Medicare patients and services, 2024

From the CMS Medicare Physician & Other Practitioners file for calendar year 2024. It counts Original Medicare patients only, so a practice that mostly sees Medicare Advantage or privately insured patients looks smaller here than it is.

Medicare patients457
Services billed 1,645 a service is one billed item, such as a visit, a test or a procedure
Average patient age73

Dollar amounts are not shown. What Medicare pays a practice is gross billings, before staff, premises and tax and including the cost of any drugs it administers, so it is not what a clinician earns.

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 $26 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 Valley Kidney Specialists, PC

Clinicians the CMS Doctors & Clinicians file lists under the same group practice. CMS counts 31 clinicians in the practice; 12 are shown here.

Other providers in Allentown