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

Dr. Mark Oldendorf, MD

Individual provider Adult Medicine Physician · NPI 1427147800

Dr. Mark Oldendorf, MD practises Internal Medicine in Loudonville, New York. Graduated from Albany Medical College of Union University in 1976, 50 years ago. Practices with Oldendorf Medical Services PLLC, an 8-clinician group, accepts Medicare assignment and offers telehealth. Licensed in New York.

Years since qualifying
50
Trained at
Albany Medical College of Union University
Licensed in
NY
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

407 Albany Shaker Rd Ste 100
Loudonville, NY 12211-1902
Phone: (518) 435-1300
Show map & directions

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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 146168 (NY)
Adult Medicine Physician Taxonomy 207QA0505X · Licence 146168 (NY)

Record details

NPI number1427147800
Entity typeIndividual (Type 1)
GenderMale
Credentials MD
Sole proprietorNo
NPI enumeratedOctober 12, 2006
Last updated in NPPESFebruary 7, 2019

Medicare enrollment

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

Medicare specialtyINTERNAL MEDICINE
Medical schoolALBANY MEDICAL COLLEGE OF UNION UNIVERSITY
Graduated 1976 (50 years in practice)
Group practice Oldendorf Medical Services Pllc — 8 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 patients377
Services billed 1,847 a service is one billed item, such as a visit, a test or a procedure
Average patient age75

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 $801 35 payments · 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. Those with a page here are linked.

Colleagues at Oldendorf Medical Services PLLC

Clinicians the CMS Doctors & Clinicians file lists under the same group practice. CMS counts 8 clinicians in the practice; 5 are shown here.