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

Amy Tesar, DO

Individual provider Internal Medicine Physician · NPI 1841307477

Amy Tesar, DO practises Internal Medicine in Mason City, Iowa. Qualified in 2002, 24 years ago. Practices with North Iowa Mercy Clinics, a 300-clinician group and accepts Medicare assignment. Licensed in Iowa.

Years since qualifying
24
Licensed in
IA
In the registry since
2006
Specialties on file
3
What do these letters mean?
DO — Doctor of Osteopathic Medicine
A fully licensed physician, trained like an MD with additional musculoskeletal training. Equivalent practice rights in all 50 states.

See every abbreviation used in this directory →

Claim this listing Report a problem Suggest an edit

Practice location Address checks out

1000 4th St SW
Mason City, IA 50401-2800
Phone: (641) 428-6999
Fax: (641) 428-6678
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

Internal Medicine Physician (primary) Taxonomy 207R00000X · Licence DO-03524 (IA)
Internal Medicine Physician Taxonomy 207R00000X · Licence 03524 (IA)
Hospitalist Physician Taxonomy 208M00000X · Licence 3524 (IA)

Record details

NPI number1841307477
Entity typeIndividual (Type 1)
GenderFemale
Credentials DO
Sole proprietorNo
NPI enumeratedAugust 23, 2006
Last updated in NPPESJuly 14, 2025
Certification dateJuly 14, 2025

Medicare enrollment

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

Medicare specialtyINTERNAL MEDICINE
Medical schoolOTHER
Graduated 2002 (24 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 patients260
Services billed 818 a service is one billed item, such as a visit, a test or a procedure
Average patient age80

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.

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.

Other providers in Mason City