Doctor profile · Federal record

Dr. William Tollefsen, MD

Emergency Medicine Physician (CMS: Emergency Medicine) · Worcester, MA

  • NPI 1841462876
  • Accepts Medicare
  • MIPS 79.9 / 100 · 2023
  • 18 yrs in practice
  • Male
  • Group practice
  • No sanctions

Practice & contact

NPPES Updated May 11, 2026
Primary practice
119 Belmont St, Department of Emergency Medicine
Worcester, MA 016052903
(508) 421-1400
fax (508) 421-1490
Mailing address
Po Box 415348
Boston, MA 022415348

Credentials & registration

NPPES · NUCC
NPI registered
March 2008 — 18 yrs on file
Profile last updated
November 13, 2012
Year of graduation
2008 — 18 yrs since
Specialty taxonomy
207P00000X — NUCC code
State license (1)
Massachusetts #243758
Medicaid
MA #110091833A

Federal sanctions & exclusions

OIG LEIE Updated May 11, 2026

No sanctions, exclusions or revocations on file

Checked against OIG LEIE on NPI 1841462876. Last verified May 11, 2026.

Medicare procedures · 2023

Top services delivered

CMS Provider Utilization
Total services
407
Distinct HCPCS
10
Medicare allowed
$57,615
HCPCS Description Services Patients Avg allowed
99285 Emergency department visit with high level of medical decision making 168 167 $183
99214 Established patient office or other outpatient visit, 30-39 minutes 55 49 $128
99284 Emergency department visit with moderate level of medical decision making 44 43 $126
99204 New patient office or other outpatient visit, 45-59 minutes 33 33 $171
99213 Established patient office or other outpatient visit, 20-29 minutes 18 17 $90
81002 Urinalysis, manual test 17 14 $3
99291 Critical care, first 30-74 minutes 17 17 $225
G0008 Administration of influenza virus vaccine 16 16 $34
99203 New patient office or other outpatient visit, 30-44 minutes 15 15 $115
71046 X-ray of chest, 2 views 12 12 $27

In context: peer comparison

Among 82 peers in Worcester Emergency Medicine Physician, average services per provider: 70. This provider delivers 5.8× the peer median.

Medicare Part D · 2023

Top prescriptions

CMS Part D Prescriber
Total claims
22
Patients
22
Total drug cost
$841
Drug Type Claims Patients Total cost
Cefpodoxime Proxetil Generic 11 11 $765
Doxycycline Hyclate Generic 11 11 $77

Hospital affiliations

CMS Hospital Compare

Frequently asked questions

Auto-generated from federal data
What is Dr. William Tollefsen's medical specialty?
Dr. William Tollefsen practices Emergency Medicine Physician in Worcester, MA.
Where does Dr. William Tollefsen practice?
Dr. William Tollefsen practices at 119 Belmont St, Worcester, MA 016052903. Office phone: 5084211400.
What is Dr. William Tollefsen's NPI?
Dr. William Tollefsen's National Provider Identifier (NPI) is 1841462876, issued by NPPES.
Does Dr. William Tollefsen accept Medicare assignment?
Yes. Dr. William Tollefsen accepts Medicare assignment, meaning Medicare-allowed amounts are accepted as full payment for covered services.
What procedures does Dr. William Tollefsen commonly perform?
Top Medicare-reported procedures in 2023: Emergency department visit with high level of medical decision making (HCPCS 99285); Established patient office or other outpatient visit (HCPCS 99214); Emergency department visit with moderate level of medical decision making (HCPCS 99284). Source: CMS Medicare Physician & Other Practitioners file.