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

John A Johnkoski

Individual provider Thoracic Surgery (Cardiothoracic Vascular Surgery) Physician · NPI 1992737035

John A Johnkoski practises Thoracic Surgery in Wausau, Wisconsin. Graduated from University of Michigan Medical School in 1988, 38 years ago. Practices with Aspirus Medical Group, Inc, a 274-clinician group and accepts Medicare assignment. Licensed in Wisconsin.

Years since qualifying
38
Trained at
University of Michigan Medical School
Licensed in
WI
In the registry since
2006
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Practice location Address checks out

425 Pine Ridge Blvd Ste 209
Wausau, WI 54401-4123 Not confirmed with CMS for 19 years — call before visiting
Phone: (715) 847-0400
Fax: (715) 847-0401
Show map & directions

Directions in Google Maps · Apple Maps · OpenStreetMap

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

Specialties & licences

Thoracic Surgery (Cardiothoracic Vascular Surgery) Physician (primary) Taxonomy 208G00000X · Licence 39318 (WI)

Record details

NPI number1992737035
Entity typeIndividual (Type 1)
GenderMale
Sole proprietorNo
NPI enumeratedJuly 7, 2006
Last updated in NPPESJuly 8, 2007

Medicare enrollment

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

Medicare specialtyTHORACIC SURGERY
Medical schoolUNIVERSITY OF MICHIGAN MEDICAL SCHOOL
Graduated 1988 (38 years in practice)
Group practice Aspirus Medical Group, Inc. — 274 clinicians
Accepts Medicare assignment Yes — accepts the Medicare-approved amount
Practice locations2 on file with Medicare

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.

Coronary artery bypass graft (CABG) 42 times · 92nd percentile
Pacemaker insertion or repair 1–10 times

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 patients185
Services billed 414 a service is one billed item, such as a visit, a test or a procedure
Average patient age74

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.

Travel and Lodging $2,249 6 payments · travel or lodging paid or reimbursed, such as to attend a conference
Food and Beverage $2,036 24 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.

Colleagues at Aspirus Medical Group, Inc

Clinicians the CMS Doctors & Clinicians file lists under the same group practice. CMS counts 274 clinicians in the practice; 12 are shown here.

Other providers in Wausau