Doctor profile · Federal record

Dr. Don Williams, MD

Internal Medicine Physician (CMS: Internal Medicine) · Oak Park, IL

  • NPI 1447288287
  • Accepts Medicare
  • MIPS 91.4 / 100 · 2023
  • 40 yrs in practice
  • Male
  • Group practice
  • No sanctions

Practice & contact

NPPES Updated May 11, 2026
Primary practice
1100 Lake St Ste 230
Oak Park, IL 603011095
(331) 221-9001
fax (331) 221-2759
Mailing address
4201 Winfield RD Fl 4
Warrenville, IL 605554025

Credentials & registration

NPPES · NUCC
NPI registered
June 2006 — 20 yrs on file
Profile last updated
May 19, 2022
Year of graduation
1986 — 40 yrs since
Specialty taxonomy
207R00000X — NUCC code
State license (1)
Illinois #036081395

Federal sanctions & exclusions

OIG LEIE Updated May 11, 2026

No sanctions, exclusions or revocations on file

Checked against OIG LEIE on NPI 1447288287. Last verified May 11, 2026.

Medicare procedures · 2023

Top services delivered

CMS Provider Utilization
Total services
509
Distinct HCPCS
7
Medicare allowed
$60,705
HCPCS Description Services Patients Avg allowed
99214 Established patient office or other outpatient visit, 30-39 minutes 239 126 $135
G0439 Annual wellness visit, includes a personalized prevention plan of service (pps), subsequent visit 109 109 $137
G0008 Administration of influenza virus vaccine 58 56 $30
90662 Influenza vaccine split virus, preservative free 55 53 $72
90677 Pneumococcal conjugate vaccine, 20 valent (pcv20), for intramuscular use 18 18 $282
G0009 Administration of pneumococcal vaccine 18 18 $32
G0438 Annual wellness visit; includes a personalized prevention plan of service (pps), initial visit 12 12 $176

In context: peer comparison

Among 19 peers in Oak Park Internal Medicine Physician, average services per provider: 82. This provider delivers 6.2× the peer median.

Medicare Part D · 2023

Top prescriptions

CMS Part D Prescriber
Total claims
1,984
Patients
566
Total drug cost
$28,369
Drug Type Claims Patients Total cost
Atorvastatin Calcium Generic 321 103 $4,359
Alprazolam Generic 184 40 $1,800
Pantoprazole Sodium Generic 149 38 $2,125
Lisinopril Generic 133 39 $1,024
Gabapentin Generic 129 36 $2,207
Metoprolol Succinate Generic 122 35 $2,818
Hydrocodone-Acetaminophen (Hydrocodone/Acetaminophen) Brand 121 27 $3,165
Metformin Hcl Generic 120 39 $1,006
Rosuvastatin Calcium Generic 118 35 $1,879
Levothyroxine Sodium Generic 110 30 $2,062

Frequently asked questions

Auto-generated from federal data
What is Dr. Don Williams's medical specialty?
Dr. Don Williams practices Internal Medicine Physician in Oak Park, IL.
Where does Dr. Don Williams practice?
Dr. Don Williams practices at 1100 Lake St Ste 230, Oak Park, IL 603011095. Office phone: 3312219001.
What is Dr. Don Williams's NPI?
Dr. Don Williams's National Provider Identifier (NPI) is 1447288287, issued by NPPES.
Does Dr. Don Williams accept Medicare assignment?
Yes. Dr. Don Williams accepts Medicare assignment, meaning Medicare-allowed amounts are accepted as full payment for covered services.
What procedures does Dr. Don Williams commonly perform?
Top Medicare-reported procedures in 2023: Established patient office or other outpatient visit (HCPCS 99214); Annual wellness visit, includes a personalized prevention plan of service (pps), subsequent visit (HCPCS G0439); Administration of influenza virus vaccine (HCPCS G0008). Source: CMS Medicare Physician & Other Practitioners file.