Doctor profile · Federal record

Dr. Margaret Johnson

Emergency Medicine Physician (CMS: Emergency Medicine) · Student in an Organized Health Care Education/Training Program · Janesville, WI

  • NPI 1821395252
  • Accepts Medicare
  • 15 yrs in practice
  • Female
  • Group practice
  • No sanctions

Practice & contact

NPPES Updated May 11, 2026
Primary practice
1000 Mineral Point Ave, Mercy Hospital
Janesville, WI 535482940
(608) 756-6000
Mailing address
822 Charing Cross RD
Madison, WI 537046010

Credentials & registration

NPPES · NUCC
NPI registered
February 2011 — 15 yrs on file
Profile last updated
September 7, 2015
Year of graduation
2011 — 15 yrs since
Specialty taxonomy
207P00000X — NUCC code
State license (1)
Wisconsin #63954-21

Federal sanctions & exclusions

OIG LEIE Updated May 11, 2026

No sanctions, exclusions or revocations on file

Checked against OIG LEIE on NPI 1821395252. Last verified May 11, 2026.

Medicare procedures · 2023

Top services delivered

CMS Provider Utilization
Total services
392
Distinct HCPCS
5
Medicare allowed
$47,131
HCPCS Description Services Patients Avg allowed
99285 Emergency department visit with high level of medical decision making 174 171 $163
93010 Routine electrocardiogram (ecg) using at least 12 leads with interpretation and report only 84 76 $8
99284 Emergency department visit with moderate level of medical decision making 71 71 $113
99291 Critical care, first 30-74 minutes 45 44 $199
99283 Emergency department visit with low level of medical decision making 18 18 $67

In context: peer comparison

Among 19 peers in Janesville Emergency Medicine Physician, average services per provider: 75. This provider delivers 5.2× the peer median.

Open Payments

Industry payments received

CMS Open Payments
All-time total
$109
Transactions
1
Manufacturers
1
Payer (manufacturer) Industry Txns Amount
Abbvie INC. 1 $108.84

By nature of payment

Food and Beverage
$109

Medicare Part D · 2023

Top prescriptions

CMS Part D Prescriber
Total claims
47
Patients
47
Total drug cost
$294
Drug Type Claims Patients Total cost
Hydrocodone-Acetaminophen (Hydrocodone/Acetaminophen) Brand 13 13 $51
Ondansetron Odt (Ondansetron) Brand 12 12 $59
Cefdinir Generic 11 11 $147
Prednisone Generic 11 11 $37

Hospital affiliations

CMS Hospital Compare

Frequently asked questions

Auto-generated from federal data
What is Dr. Margaret Johnson's medical specialty?
Dr. Margaret Johnson practices Emergency Medicine Physician in Janesville, WI.
Where does Dr. Margaret Johnson practice?
Dr. Margaret Johnson practices at 1000 Mineral Point Ave, Janesville, WI 535482940. Office phone: 6087566000.
What is Dr. Margaret Johnson's NPI?
Dr. Margaret Johnson's National Provider Identifier (NPI) is 1821395252, issued by NPPES.
Does Dr. Margaret Johnson accept Medicare assignment?
Yes. Dr. Margaret Johnson accepts Medicare assignment, meaning Medicare-allowed amounts are accepted as full payment for covered services.
What procedures does Dr. Margaret Johnson commonly perform?
Top Medicare-reported procedures in 2023: Emergency department visit with high level of medical decision making (HCPCS 99285); Routine electrocardiogram (ecg) using at least 12 leads with interpretation and report only (HCPCS 93010); Emergency department visit with moderate level of medical decision making (HCPCS 99284). Source: CMS Medicare Physician & Other Practitioners file.