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

Dr. Mark Warren Hiser, MD

Individual provider Cardiovascular Disease Physician · NPI 1538184924

Dr. Mark Warren Hiser, MD practises Cardiac Electrophysiology in Rockford, Illinois. Qualified in 1972, 54 years ago. Practices with Osf Multi-Specialty Group, a 2,128-clinician group and accepts Medicare assignment. Licensed in Illinois.

Years since qualifying
54
Licensed in
IL
In the registry since
2006
Specialties on file
5
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

444 Roxbury Rd
Rockford, IL 61107-5059 Not confirmed with CMS for 17 years — call before visiting
Phone: (815) 398-3000
Fax: (815) 398-3041
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Pin is approximate — placed at the ZIP-code centre, not the exact door.

Specialties & licences

Cardiovascular Disease Physician (primary) Taxonomy 207RC0000X · Licence 36055207 (IL)
Clinical Cardiac Electrophysiology Physician Taxonomy 207RC0001X · Licence 36055207 (IL)
Interventional Cardiology Physician Taxonomy 207RI0011X · Licence 36055207 (IL)
Body Imaging Physician Taxonomy 2085B0100X · Licence 36055207 (IL)
Diagnostic Ultrasound Physician Taxonomy 2085U0001X · Licence 36055207 (IL)

Record details

NPI number1538184924
Entity typeIndividual (Type 1)
GenderMale
Credentials MD
Sole proprietorNo
NPI enumeratedJuly 13, 2006
Last updated in NPPESNovember 11, 2009

Medicare enrollment

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

Medicare specialtyCARDIAC ELECTROPHYSIOLOGY
Also practisesCARDIOVASCULAR DISEASE (CARDIOLOGY)
Medical schoolOTHER
Graduated 1972 (54 years in practice)
Group practice Osf Multi-Specialty Group — 2128 clinicians
Accepts Medicare assignment Yes — accepts the Medicare-approved amount

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 patients398
Services billed 927 a service is one billed item, such as a visit, a test or a procedure
Average patient age79

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 $44 2 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 Osf Multi-Specialty Group

Clinicians the CMS Doctors & Clinicians file lists under the same group practice. CMS counts 2128 clinicians in the practice; 12 are shown here.

Other providers in Rockford