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

Stephen Peter Kayiaros, MD

Individual provider Adult Reconstructive Orthopaedic Surgery Physician · NPI 1669699542

Stephen Peter Kayiaros, MD practises Orthopedic Surgery in Princeton, New Jersey. Graduated from Rutgers New Jersey Medical School in 2005, 21 years ago. Practices with Orthonj LLC, a 301-clinician group and accepts Medicare assignment. Licensed in New Jersey.

Years since qualifying
21
Trained at
Rutgers New Jersey Medical School
Licensed in
NJ
In the registry since
2007
Specialties on file
3
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

211 N Harrison St
Princeton, NJ 08540-3530
Phone: (609) 683-7800
Fax: (609) 683-7875
Show map & directions

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Pin is approximate — placed at the ZIP-code centre, not the exact door.

Specialties & licences

Orthopaedic Surgery Physician (primary) Taxonomy 207X00000X · Licence 25MA09077600 (NJ)
Adult Reconstructive Orthopaedic Surgery Physician Taxonomy 207XS0114X · Licence 25MA09077600 (NJ)
Orthopaedic Trauma Physician Taxonomy 207XX0801X · Licence 25MA09077600 (NJ)

Record details

NPI number1669699542
Entity typeIndividual (Type 1)
GenderMale
Credentials MD
Sole proprietorNo
NPI enumeratedApril 20, 2007
Last updated in NPPESJune 15, 2020
Certification dateJune 15, 2020

Medicare enrollment

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

Medicare specialtyORTHOPEDIC SURGERY
Medical schoolRUTGERS NEW JERSEY MEDICAL SCHOOL
Graduated 2005 (21 years in practice)
Group practice Orthonj Llc — 301 clinicians
Accepts Medicare assignment Yes — accepts the Medicare-approved amount

Procedures

From CMS Care Compare, which counts the procedures a clinician billed to Original Medicare and Medicare Advantage over a recent 12-month period. CMS reports a fixed list of common procedures, so this is not everything the clinician does. Counts of 10 or fewer are given as a range, because CMS withholds small numbers.

Hip replacement 116 times · 98th percentile
Knee replacement 105 times · 94th percentile

The percentile compares how often this clinician performed the procedure with other clinicians who performed it, as CMS calculates it. It measures volume, not outcomes or skill.

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 patients695
Services billed 5,103 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.

Consulting Fee $3,240 3 payments
Food and Beverage $796 11 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.

Also affiliated with 1 inpatient rehabilitation facility, which CMS identifies by certification number only.

Colleagues at Orthonj LLC

Clinicians the CMS Doctors & Clinicians file lists under the same group practice. CMS counts 301 clinicians in the practice; 12 are shown here.

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