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

Gregory K Sewall, MD

Individual provider Otolaryngology Physician · NPI 1336195023

Gregory K Sewall, MD practises Otolaryngology in Wausau, Wisconsin. Graduated from Medical College of Wisconsin in 1999, 27 years ago. Practices with ENT and Allergy Associates SC, a 25-clinician group and accepts Medicare assignment. Licensed in Wisconsin.

Years since qualifying
27
Trained at
Medical College of Wisconsin
Licensed in
WI
In the registry since
2006
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

512 S 28th Ave
Wausau, WI 54401-4147
Phone: (715) 847-2021
Fax: (715) 847-2325
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Pin is approximate — placed at the ZIP-code centre, not the exact door.

Specialties & licences

Otolaryngology Physician (primary) Taxonomy 207Y00000X · Licence 42332-020 (WI)

Record details

NPI number1336195023
Entity typeIndividual (Type 1)
GenderMale
Credentials MD
Sole proprietorNo
NPI enumeratedMay 25, 2006
Last updated in NPPESApril 13, 2020
Certification dateApril 13, 2020

Medicare enrollment

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

Medicare specialtyOTOLARYNGOLOGY
Medical schoolMEDICAL COLLEGE OF WISCONSIN
Graduated 1999 (27 years in practice)
Group practice Ent And Allergy Associates Sc — 25 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.

Skin biopsy 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 patients191
Services billed 354 a service is one billed item, such as a visit, a test or a procedure
Average patient age72

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 $85 4 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 ENT and Allergy Associates SC

Clinicians the CMS Doctors & Clinicians file lists under the same group practice. CMS counts 25 clinicians in the practice; 12 are shown here.

Other providers in Wausau