Daniel Hamilos,

Daniel Hamilos, MD

Allergy and Immunology

Primary Contact

641-494-5380

About

Daniel Hamilos, MD, provides allergy care at MercyOne North Iowa Allergy and Immunology in Mason City. He understands how nasal allergies and frequent sinus infections can make someone feel miserable. “It makes me happy when you finally get relief,” Daniel said.

Daniel grew up in Illinois and attended medical school at Northwestern University in Chicago. He is certified by the American Board of Allergy and Immunology.

At MercyOne, Daniel treats many allergy-related conditions like asthma, eczema and food allergies. He can also diagnose and treat immune system disorders, which is how your body defends against infections.

Outside the clinic, Daniel walks, bikes and plays baseball or softball to stay in good health. He and his wife attend church and enjoy visiting family.

Services & Specialties

Areas of Specialization

  • Allergy and Immunology

Locations & Contact

Primary Location

MercyOne North Iowa Allergy and Immunology

250 S. Crescent Drive
Suite M1400
Mason City, IA 50401

View hours
Monday
8:00am - 5:00pm
Tuesday
8:00am - 5:00pm
Wednesday
8:00am - 5:00pm
Thursday
8:00am - 5:00pm
Friday
8:00am - 5:00pm
MercyOne North Iowa Allergy and Immunology

Education & Certifications

Education

Medical School:
Northwestern University; Chicago, Illinois

Board Certifications

Internal Medicine, American Board of Internal Medicine

Provider Ratings

The following ratings and reviews are based on verified feedback collected from independently administered patient experience surveys. The ratings and comments submitted by patients reflect their own views and opinions. Patient identities are withheld to ensure confidentiality and privacy. Learn More >

4.8 out of 5

(33 ratings)

The Patient Satisfaction Rating is an average of all responses to the care provider related questions shown below from our survey. Patients that are treated in outpatient or hospital environments may receive different surveys, and the volume of responses will vary by question.

5 Reviews

07/17/2026

Great provider!

06/11/2026

He is very nice, explained everything, was focused on me/my health/issues and gave me time..

06/09/2026

I would recommend him to others needing allergy testing.

06/03/2026

Again, I was very impressed with Dr. Hamilos. I trust his wisdom, skills, and compassion. He is a credit to the Mercy One organization.

05/19/2026

Dr. Hamilos is THE BEST. He is genuine in his care for his patients. He respectfully listens to what we have to say and provides thoughtful, knowledgeable answers. Thanks to him, I'm back to enjoying things in life my allergies were previously keeping me from!