Provider records sourced from NPPES (CMS National Plan & Provider Enumeration System). Data current as of August 10, 2026.
NPIDirectory

Dr. Demetrios Spyridon Theodoropoulos, MD

Individual provider Clinical & Laboratory Immunology (Allergy & Immunology) Physician · NPI 1326299488

Dr. Demetrios Spyridon Theodoropoulos, MD practises Allergy/Immunology in Onalaska, Wisconsin. Qualified in 1987, 39 years ago. Practices with Allergy Associates Holdings, Ltd, a 5-clinician group, accepts Medicare assignment and offers telehealth. Licensed in Wisconsin.

Years since qualifying
39
Licensed in
WI
In the registry since
2008
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

2727 Midwest Dr
Onalaska, WI 54650 Not confirmed with CMS for 10 years — call before visiting
Phone: (608) 782-2027
Fax: (608) 782-6172
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Pin is approximate — placed at the ZIP-code centre, not the exact door.

Specialties & licences

Clinical & Laboratory Immunology (Allergy & Immunology) Physician (primary) Taxonomy 207KI0005X · Licence 44060-20 (WI)

Record details

NPI number1326299488
Entity typeIndividual (Type 1)
GenderMale
Credentials MD
Sole proprietorNo
NPI enumeratedOctober 8, 2008
Last updated in NPPESDecember 14, 2015

Medicare enrollment

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

Medicare specialtyALLERGY/IMMUNOLOGY
Medical schoolOTHER
Graduated 1987 (39 years in practice)
Group practice Allergy Associates Holdings, Ltd — 5 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 patients216
Services billed 2,683 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 $764 27 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.

Colleagues at Allergy Associates Holdings, Ltd

Clinicians the CMS Doctors & Clinicians file lists under the same group practice.