Doctor profile · Federal record

Dr. Derek Timmermann, M.D.

Emergency Medicine Physician (CMS: Emergency Medicine) · Rockford, IL

  • NPI 1649213141
  • Accepts Medicare
  • MIPS 98.4 / 100 · 2023
  • 26 yrs in practice
  • Male
  • Group practice
  • No sanctions

Practice & contact

NPPES Updated May 11, 2026
Primary practice
5666 E State St, Emergency Department
Rockford, IL 611082425
(815) 395-5189

Credentials & registration

NPPES · NUCC
NPI registered
June 2006 — 20 yrs on file
Profile last updated
August 31, 2012
Year of graduation
2000 — 26 yrs since
Specialty taxonomy
207P00000X — NUCC code
State license (1)
Illinois #036.118970
Medicaid
CA #WA91176B

Federal sanctions & exclusions

OIG LEIE Updated May 11, 2026

No sanctions, exclusions or revocations on file

Checked against OIG LEIE on NPI 1649213141. Last verified May 11, 2026.

Medicare procedures · 2023

Top services delivered

CMS Provider Utilization
Total services
666
Distinct HCPCS
4
Medicare allowed
$110,110
HCPCS Description Services Patients Avg allowed
99285 Emergency department visit with high level of medical decision making 523 483 $175
99284 Emergency department visit with moderate level of medical decision making 80 77 $120
99291 Critical care, first 30-74 minutes 42 42 $210
93042 Electrocardiogram (ecg) 1 to 3 leads with review by physician only 21 21 $7

In context: peer comparison

Among 18 peers in this city , average services per provider: 111. This provider delivers 6.0× the peer median.

Medicare Part D · 2023

Top prescriptions

CMS Part D Prescriber
Total claims
188
Patients
184
Total drug cost
$919
Drug Type Claims Patients Total cost
Hydrocodone-Acetaminophen (Hydrocodone/Acetaminophen) Brand 51 51 $325
Prednisone Generic 33 31 $57
Tramadol Hcl Generic 23 23 $49
Cephalexin Generic 21 21 $146
Lorazepam Generic 16 16 $58
Ondansetron Odt (Ondansetron) Brand 16 15 $76
Amoxicillin-Clavulanate Potass (Amoxicillin/Potassium Clav) Brand 14 14 $139
Meclizine Hcl Generic 14 13 $70

Hospital affiliations

CMS Hospital Compare

Frequently asked questions

Auto-generated from federal data
What is Dr. Derek Timmermann's medical specialty?
Dr. Derek Timmermann practices Emergency Medicine Physician in Rockford, IL.
Where does Dr. Derek Timmermann practice?
Dr. Derek Timmermann practices at 5666 E State St, Rockford, IL 611082425. Office phone: 8153955189.
What is Dr. Derek Timmermann's NPI?
Dr. Derek Timmermann's National Provider Identifier (NPI) is 1649213141, issued by NPPES.
Does Dr. Derek Timmermann accept Medicare assignment?
Yes. Dr. Derek Timmermann accepts Medicare assignment, meaning Medicare-allowed amounts are accepted as full payment for covered services.
What procedures does Dr. Derek Timmermann commonly perform?
Top Medicare-reported procedures in 2023: Emergency department visit with high level of medical decision making (HCPCS 99285); Emergency department visit with moderate level of medical decision making (HCPCS 99284); Critical care (HCPCS 99291). Source: CMS Medicare Physician & Other Practitioners file.