Doctor profile · Federal record

Dr. Dan Williams, PA, PSYD

Medical Physician Assistant (CMS: Physician Assistant) · Medical Physician Assistant · Janesville, WI

  • NPI 1801874664
  • Accepts Medicare
  • 45 yrs in practice
  • Licensed in 2 states
  • Male
  • Group practice
  • No sanctions

Practice & contact

NPPES Updated May 11, 2026
Primary practice
3524 E Milwaukee St
Janesville, WI 535461626
(608) 756-7100
fax (608) 756-4700

Credentials & registration

NPPES · NUCC
NPI registered
January 2006 — 20 yrs on file
Profile last updated
October 26, 2016
Year of graduation
1981 — 45 yrs since
Specialty taxonomy
363AM0700X — NUCC code
State licenses (2)
Wisconsin #3873-23 · Illinois #8500535
Medicaid
WI #1801874664

Federal sanctions & exclusions

OIG LEIE Updated May 11, 2026

No sanctions, exclusions or revocations on file

Checked against OIG LEIE on NPI 1801874664. Last verified May 11, 2026.

Medicare procedures · 2023

Top services delivered

CMS Provider Utilization
Total services
551
Distinct HCPCS
10
Medicare allowed
$35,590
HCPCS Description Services Patients Avg allowed
99213 Established patient office or other outpatient visit, 20-29 minutes 203 158 $74
99203 New patient office or other outpatient visit, 30-44 minutes 122 122 $92
87811 Detection test by immunoassay with direct visual observation for severe acute respiratory syndrome coronavirus 2 (covid-19) 72 67 $41
81003 Automated urinalysis test 38 35 $2
99214 Established patient office or other outpatient visit, 30-39 minutes 25 24 $104
71046 X-ray of chest, 2 views 24 24 $9
87880 Detection test by immunoassay with direct visual observation for streptococcus, group a (strep) 21 21 $16
99204 New patient office or other outpatient visit, 45-59 minutes 21 21 $137
69209 Removal of impacted ear wax by washing 14 13 $15
93000 Routine electrocardiogram (ecg) using at least 12 leads with interpretation and report 11 11 $12

In context: peer comparison

Among 4 peers in this city , average services per provider: 146. This provider delivers 3.8× the peer median.

Medicare Part D · 2023

Top prescriptions

CMS Part D Prescriber
Total claims
611
Patients
573
Total drug cost
$4,118
Drug Type Claims Patients Total cost
Prednisone Generic 188 178 $319
Doxycycline Hyclate Generic 69 66 $834
Cephalexin Generic 53 49 $321
Nitrofurantoin Mono-Macro (Nitrofurantoin Monohyd/M-Cryst) Brand 52 46 $459
Amoxicillin Generic 38 38 $161
Ciprofloxacin Hcl Generic 33 32 $148
Tramadol Hcl Generic 30 29 $67
Azithromycin Generic 29 28 $163
Amoxicillin-Clavulanate Potass (Amoxicillin/Potassium Clav) Brand 26 26 $196
Clindamycin Hcl Generic 24 24 $148

Frequently asked questions

Auto-generated from federal data
What is Dr. Dan Williams's medical specialty?
Dr. Dan Williams practices Medical Physician Assistant in Janesville, WI.
Where does Dr. Dan Williams practice?
Dr. Dan Williams practices at 3524 E Milwaukee St, Janesville, WI 535461626. Office phone: 6087567100.
What is Dr. Dan Williams's NPI?
Dr. Dan Williams's National Provider Identifier (NPI) is 1801874664, issued by NPPES.
Does Dr. Dan Williams accept Medicare assignment?
Yes. Dr. Dan Williams accepts Medicare assignment, meaning Medicare-allowed amounts are accepted as full payment for covered services.
What procedures does Dr. Dan Williams commonly perform?
Top Medicare-reported procedures in 2023: Established patient office or other outpatient visit (HCPCS 99213); New patient office or other outpatient visit (HCPCS 99203); Detection test by immunoassay with direct visual observation for severe acute respiratory syndrome coronavirus 2 (covid-19) (HCPCS 87811). Source: CMS Medicare Physician & Other Practitioners file.