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

Dr. Daniel L Hamilos, MD

Individual provider Allergy & Immunology Physician · NPI 1558347047

Dr. Daniel L Hamilos, MD practises Allergy/Immunology in Mason City, Iowa. Graduated from Northwestern University Feinberg Medical School in 1979, 47 years ago. Practices with North Iowa Mercy Clinics, a 300-clinician group and accepts Medicare assignment. Licensed in Iowa and Massachusetts.

Years since qualifying
47
Trained at
Northwestern University Feinberg Medical School
Licensed in
IA, MA
In the registry since
2005
Specialties on file
4
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

250 S Crescent Dr
Mason City, IA 50401-2926
Phone: (641) 494-5380
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Pin is approximate — placed at the ZIP-code centre, not the exact door.

Specialties & licences

Allergy & Immunology Physician (primary) Taxonomy 207K00000X · Licence 52071 (IA)
Allergy & Immunology Physician Taxonomy 207K00000X · Licence 219164 (MA)
Clinical & Laboratory Immunology (Allergy & Immunology) Physician Taxonomy 207KI0005X · Licence 219164 (MA)
Internal Medicine Physician Taxonomy 207R00000X · Licence 219164 (MA)

Record details

NPI number1558347047
Entity typeIndividual (Type 1)
GenderMale
Credentials MD
Sole proprietorNo
NPI enumeratedDecember 16, 2005
Last updated in NPPESOctober 23, 2023
Certification dateOctober 23, 2023

Medicare enrollment

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

Medicare specialtyALLERGY/IMMUNOLOGY
Medical schoolNORTHWESTERN UNIVERSITY FEINBERG MEDICAL SCHOOL
Graduated 1979 (47 years in practice)
Group practice North Iowa Mercy Clinics — 300 clinicians
Accepts Medicare assignment Yes — accepts the Medicare-approved amount
Practice locations2 on file with Medicare

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 patients125
Services billed 357 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 $70 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 North Iowa Mercy Clinics

Clinicians the CMS Doctors & Clinicians file lists under the same group practice. CMS counts 300 clinicians in the practice; 12 are shown here.