Doctor profile · Federal record

Dr. William Callahan, O.D.

Optometrist (CMS: Optometry) · Marshfield, MA

  • NPI 1568536357
  • Accepts Medicare
  • 43 yrs in practice
  • Male
  • Solo practice
  • No sanctions

Practice & contact

NPPES Updated May 11, 2026
Primary practice
462 Plain St, Suite 104
Marshfield, MA 020502731
(781) 837-9956
fax (781) 837-9950

Credentials & registration

NPPES · NUCC
NPI registered
November 2006 — 20 yrs on file
Profile last updated
August 23, 2012
Year of graduation
1983 — 43 yrs since
Specialty taxonomy
152W00000X — NUCC code
State license (1)
Massachusetts #3071
Medicaid
MA #0352276

Federal sanctions & exclusions

OIG LEIE Updated May 11, 2026

No sanctions, exclusions or revocations on file

Checked against OIG LEIE on NPI 1568536357. Last verified May 11, 2026.

Medicare procedures · 2023

Top services delivered

CMS Provider Utilization
Total services
619
Distinct HCPCS
7
Medicare allowed
$46,994
HCPCS Description Services Patients Avg allowed
92012 Established patient problem focused exam of visual system 183 118 $93
92250 Photography of the retina 115 111 $36
92285 Photography of content of eyes 112 110 $24
92083 Exam of visual field with extended testing 76 74 $65
92014 Established patient complete exam of visual system 72 72 $131
92004 New patient complete exam of visual system 50 50 $155
92002 New patient problem focused exam of visual system 11 11 $89

In context: peer comparison

Among 1 peers in this city , average services per provider: 88. This provider delivers 7.0× the peer median.

Medicare Part D · 2023

Top prescriptions

CMS Part D Prescriber
Total claims
29
Patients
0
Total drug cost
$20,889
Drug Type Claims Patients Total cost
Restasis (Cyclosporine) Brand 18 0 $20,854
Levofloxacin Generic 11 0 $35

Frequently asked questions

Auto-generated from federal data
What is Dr. William Callahan's medical specialty?
Dr. William Callahan practices Optometrist in Marshfield, MA.
Where does Dr. William Callahan practice?
Dr. William Callahan practices at 462 Plain St, Marshfield, MA 020502731. Office phone: 7818379956.
What is Dr. William Callahan's NPI?
Dr. William Callahan's National Provider Identifier (NPI) is 1568536357, issued by NPPES.
Does Dr. William Callahan accept Medicare assignment?
Yes. Dr. William Callahan accepts Medicare assignment, meaning Medicare-allowed amounts are accepted as full payment for covered services.
What procedures does Dr. William Callahan commonly perform?
Top Medicare-reported procedures in 2023: Established patient problem focused exam of visual system (HCPCS 92012); Photography of the retina (HCPCS 92250); Photography of content of eyes (HCPCS 92285). Source: CMS Medicare Physician & Other Practitioners file.