Doctor profile · Federal record

Dr. Gad Marshall, MD

Neurology Physician (CMS: Neurology) · Boston, MA

  • NPI 1639105513
  • Accepts Medicare
  • 26 yrs in practice
  • Male
  • Group practice
  • No sanctions

Practice & contact

NPPES Updated May 11, 2026
Primary practice
Bwh Memory Disorder Unit, 221 Longwood Ave
Boston, MA 02115
(617) 732-8085
fax (617) 738-9122

Credentials & registration

NPPES · NUCC
NPI registered
June 2006 — 20 yrs on file
Profile last updated
July 8, 2007
Year of graduation
2000 — 26 yrs since
Specialty taxonomy
2084N0400X — NUCC code
State license (1)
California #A85728

Federal sanctions & exclusions

OIG LEIE Updated May 11, 2026

No sanctions, exclusions or revocations on file

Checked against OIG LEIE on NPI 1639105513. Last verified May 11, 2026.

Medicare procedures · 2023

Top services delivered

CMS Provider Utilization
Total services
185
Distinct HCPCS
4
Medicare allowed
$18,983
HCPCS Description Services Patients Avg allowed
G2212 Prolonged office or other outpatient evaluation and management service(s) beyond the maximum required time of the primary procedure which has been selected using total time on the date of the primary service; each additional 15 minutes by the physician or 77 17 $33
99215 Established patient office or other outpatient visit, 40-54 minutes 72 46 $153
99205 New patient office or other outpatient visit, 60-74 minutes 19 19 $193
99214 Established patient office or other outpatient visit, 30-39 minutes 17 15 $104

In context: peer comparison

Among 134 peers in Boston Neurology Physician, average services per provider: 234. This provider delivers 0.8× the peer median.

Medicare Part D · 2023

Top prescriptions

CMS Part D Prescriber
Total claims
238
Patients
43
Total drug cost
$5,045
Drug Type Claims Patients Total cost
Donepezil Hcl Generic 82 20 $1,379
Trazodone Hcl Generic 44 12 $1,074
Escitalopram Oxalate Generic 40 11 $524
Risperidone Generic 29 0 $271
Memantine Hcl Generic 15 0 $644
Methylphenidate Hcl Generic 14 0 $804
Sertraline Hcl Generic 14 0 $347

Hospital affiliations

CMS Hospital Compare

Frequently asked questions

Auto-generated from federal data
What is Dr. Gad Marshall's medical specialty?
Dr. Gad Marshall practices Neurology Physician in Boston, MA.
Where does Dr. Gad Marshall practice?
Dr. Gad Marshall practices at Bwh Memory Disorder Unit, Boston, MA 02115. Office phone: 6177328085.
What is Dr. Gad Marshall's NPI?
Dr. Gad Marshall's National Provider Identifier (NPI) is 1639105513, issued by NPPES.
Does Dr. Gad Marshall accept Medicare assignment?
Yes. Dr. Gad Marshall accepts Medicare assignment, meaning Medicare-allowed amounts are accepted as full payment for covered services.
What procedures does Dr. Gad Marshall commonly perform?
Top Medicare-reported procedures in 2023: Prolonged office or other outpatient evaluation and management service(s) beyond the maximum required time of the primary procedure which has been selected using total time on the date of the primary service; each additional 15 minutes by the physician or (HCPCS G2212); Established patient office or other outpatient visit (HCPCS 99215); New patient office or other outpatient visit (HCPCS 99205). Source: CMS Medicare Physician & Other Practitioners file.