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

Individual provider Emergency Medicine Physician · NPI 1649213141

Derek Timmermann, MD practises Emergency Medicine in Rockford, Illinois. Graduated from Stanford University School of Medicine in 2000, 26 years ago. Practices with Cepamerica Illinois LLP, a 493-clinician group and accepts Medicare assignment. Licensed in Illinois.

Years since qualifying
26
Trained at
Stanford University School of Medicine
Licensed in
IL
In the registry since
2006
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

5666 E State St Emergency Dept
Rockford, IL 61108-2425 Not confirmed with CMS for 14 years — call before visiting
Phone: (815) 395-5189
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Pin is approximate — placed at the ZIP-code centre, not the exact door.

Specialties & licences

Emergency Medicine Physician (primary) Taxonomy 207P00000X · Licence 036.118970 (IL)

Record details

NPI number1649213141
Entity typeIndividual (Type 1)
GenderMale
Credentials MD
Sole proprietorNo
NPI enumeratedJune 13, 2006
Last updated in NPPESAugust 31, 2012

Medicare enrollment

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

Medicare specialtyEMERGENCY MEDICINE
Medical schoolSTANFORD UNIVERSITY SCHOOL OF MEDICINE
Graduated 2000 (26 years in practice)
Group practice Cepamerica Illinois Llp — 493 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 patients466
Services billed 503 a service is one billed item, such as a visit, a test or a procedure
Average patient age75

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 Cepamerica Illinois LLP

Clinicians the CMS Doctors & Clinicians file lists under the same group practice. CMS counts 493 clinicians in the practice; 12 are shown here.

Other providers in Rockford