Doctor profile · Federal record

Dr. William Kobak, M.D.

Gynecology Physician (CMS: Obstetrics/Gynecology) · Obstetrics & Gynecology Physician · St Charles, IL

  • NPI 1023007887
  • Accepts Medicare
  • MIPS 71.4 / 100 · 2023
  • 37 yrs in practice
  • Male
  • Group practice
  • No sanctions

Practice & contact

NPPES Updated May 11, 2026
Primary practice
3310 W Main St, Suite 200
St Charles, IL 601751000
(630) 897-6044
fax (630) 897-0180
Mailing address
Po Box 657
St Charles, IL 601740657

Credentials & registration

NPPES · NUCC
NPI registered
October 2005 — 21 yrs on file
Profile last updated
January 29, 2025
Year of graduation
1989 — 37 yrs since
Specialty taxonomy
207VG0400X — NUCC code
State license (1)
Illinois #036091917
Medicaid
IL #036091917

Federal sanctions & exclusions

OIG LEIE Updated May 11, 2026

No sanctions, exclusions or revocations on file

Checked against OIG LEIE on NPI 1023007887. Last verified May 11, 2026.

Medicare procedures · 2023

Top services delivered

CMS Provider Utilization
Total services
84
Distinct HCPCS
2
Medicare allowed
$5,020
HCPCS Description Services Patients Avg allowed
99213 Established patient office or other outpatient visit, 20-29 minutes 58 34 $70
99212 Established patient office or other outpatient visit, 10-19 minutes 26 20 $38

In context: peer comparison

Among 1 peers in St Charles Gynecology Physician, average services per provider: 42. This provider delivers 2.0× the peer median.

Open Payments

Industry payments received

CMS Open Payments
All-time total
$13
Transactions
1
Manufacturers
1
Payer (manufacturer) Industry Txns Amount
Boston Scientific Corporation 1 $13.18

By nature of payment

Food and Beverage
$13

Medicare Part D · 2023

Top prescriptions

CMS Part D Prescriber
Total claims
248
Patients
96
Total drug cost
$43,192
Drug Type Claims Patients Total cost
Estradiol Generic 61 26 $6,055
Oxybutynin Chloride ER (Oxybutynin Chloride) Brand 43 14 $1,284
Myrbetriq (Mirabegron) Brand 40 12 $25,550
Solifenacin Succinate Generic 39 20 $6,710
Methenamine Hippurate Generic 38 0 $3,362
Nitrofurantoin Mono-Macro (Nitrofurantoin Monohyd/M-Cryst) Brand 14 11 $196
Oxycodone Hcl Generic 13 13 $35

Hospital affiliations

CMS Hospital Compare

Frequently asked questions

Auto-generated from federal data
What is Dr. William Kobak's medical specialty?
Dr. William Kobak practices Gynecology Physician in St Charles, IL.
Where does Dr. William Kobak practice?
Dr. William Kobak practices at 3310 W Main St, St Charles, IL 601751000. Office phone: 6308976044.
What is Dr. William Kobak's NPI?
Dr. William Kobak's National Provider Identifier (NPI) is 1023007887, issued by NPPES.
Does Dr. William Kobak accept Medicare assignment?
Yes. Dr. William Kobak accepts Medicare assignment, meaning Medicare-allowed amounts are accepted as full payment for covered services.
What procedures does Dr. William Kobak commonly perform?
Top Medicare-reported procedures in 2023: Established patient office or other outpatient visit (HCPCS 99213); Established patient office or other outpatient visit (HCPCS 99212). Source: CMS Medicare Physician & Other Practitioners file.