Doctor profile · Federal record

Dr. Katherine Diemer, MD

Family Medicine Physician (CMS: Family Practice) · Family Medicine Physician · Freeport, IL

  • NPI 1396906749
  • Accepts Medicare
  • 20 yrs in practice
  • Licensed in 2 states
  • Female
  • Group practice
  • No sanctions

Practice & contact

NPPES Updated May 11, 2026
Primary practice
1301 Kiwanis Dr
Freeport, IL 610326907
(815) 235-1406
Mailing address
515 22Nd Ave
Monroe, WI 535661569

Credentials & registration

NPPES · NUCC
NPI registered
June 2008 — 18 yrs on file
Profile last updated
December 18, 2020
Year of graduation
2006 — 20 yrs since
Specialty taxonomy
207Q00000X — NUCC code
State licenses (2)
Illinois #125051266 · Wisconsin #57640

Federal sanctions & exclusions

OIG LEIE Updated May 11, 2026

No sanctions, exclusions or revocations on file

Checked against OIG LEIE on NPI 1396906749. Last verified May 11, 2026.

Medicare procedures · 2023

Top services delivered

CMS Provider Utilization
Total services
511
Distinct HCPCS
4
Medicare allowed
$46,358
HCPCS Description Services Patients Avg allowed
99214 Established patient office or other outpatient visit, 30-39 minutes 247 138 $96
99213 Established patient office or other outpatient visit, 20-29 minutes 180 115 $65
G0439 Annual wellness visit, includes a personalized prevention plan of service (pps), subsequent visit 73 73 $126
G0438 Annual wellness visit; includes a personalized prevention plan of service (pps), initial visit 11 11 $162

In context: peer comparison

Among 8 peers in Freeport Family Medicine Physician, average services per provider: 98. This provider delivers 5.2× the peer median.

Medicare Part D · 2023

Top prescriptions

CMS Part D Prescriber
Total claims
2,526
Patients
661
Total drug cost
$36,305
Drug Type Claims Patients Total cost
Lisinopril Generic 293 80 $3,153
Atorvastatin Calcium Generic 275 72 $3,361
Levothyroxine Sodium Generic 246 56 $3,119
Amlodipine Besylate Generic 204 55 $1,553
Hydrocodone-Acetaminophen (Hydrocodone/Acetaminophen) Brand 197 57 $6,291
Metformin Hcl Generic 190 55 $1,377
Furosemide Generic 150 36 $789
Gabapentin Generic 148 36 $3,560
Hydrochlorothiazide Generic 128 38 $603
Metoprolol Succinate Generic 122 28 $3,208

Frequently asked questions

Auto-generated from federal data
What is Dr. Katherine Diemer's medical specialty?
Dr. Katherine Diemer practices Family Medicine Physician in Freeport, IL.
Where does Dr. Katherine Diemer practice?
Dr. Katherine Diemer practices at 1301 Kiwanis Dr, Freeport, IL 610326907. Office phone: 8152351406.
What is Dr. Katherine Diemer's NPI?
Dr. Katherine Diemer's National Provider Identifier (NPI) is 1396906749, issued by NPPES.
Does Dr. Katherine Diemer accept Medicare assignment?
Yes. Dr. Katherine Diemer accepts Medicare assignment, meaning Medicare-allowed amounts are accepted as full payment for covered services.
What procedures does Dr. Katherine Diemer commonly perform?
Top Medicare-reported procedures in 2023: Established patient office or other outpatient visit (HCPCS 99214); Established patient office or other outpatient visit (HCPCS 99213); Annual wellness visit, includes a personalized prevention plan of service (pps), subsequent visit (HCPCS G0439). Source: CMS Medicare Physician & Other Practitioners file.