Doctor profile · Federal record

Dr. Mark Nitzberg, M.D.

Gastroenterology Physician (CMS: Gastroenterology) · Methuen, MA

  • NPI 1881652758
  • Accepts Medicare
  • 37 yrs in practice
  • Male
  • Solo practice
  • No sanctions

Practice & contact

NPPES Updated May 11, 2026
Primary practice
38R Merrimack St., Suite 2C
Methuen, MA 01844
(978) 681-1977
fax (978) 686-8918
Mailing address
380R Merrimack St., Suite 2C
Methuen, MA 01844

Credentials & registration

NPPES · NUCC
NPI registered
May 2006 — 20 yrs on file
Profile last updated
November 16, 2017
Year of graduation
1989 — 37 yrs since
Specialty taxonomy
207RG0100X — NUCC code
State license (1)
Massachusetts #74584

Federal sanctions & exclusions

OIG LEIE Updated May 11, 2026

No sanctions, exclusions or revocations on file

Checked against OIG LEIE on NPI 1881652758. Last verified May 11, 2026.

Medicare procedures · 2023

Top services delivered

CMS Provider Utilization
Total services
333
Distinct HCPCS
10
Medicare allowed
$48,108
HCPCS Description Services Patients Avg allowed
99203 New patient office or other outpatient visit, 30-44 minutes 61 61 $110
99213 Established patient office or other outpatient visit, 20-29 minutes 61 54 $91
45380 Biopsy of large bowel using a flexible endoscope 42 42 $200
43239 Biopsy of esophagus, stomach, and/or upper small bowel using a flexible endoscope 38 38 $103
45385 Removal of polyps or growths of large bowel using an endoscope with mechanical snare 30 30 $243
45380 Biopsy of large bowel using a flexible endoscope 28 28 $196
45378 Diagnostic exam of large bowel using a flexible endoscope 21 20 $179
43239 Biopsy of esophagus, stomach, and/or upper small bowel using a flexible endoscope 20 20 $111
G0439 Annual wellness visit, includes a personalized prevention plan of service (pps), subsequent visit 20 20 $132
G0105 Colorectal cancer screening; colonoscopy on individual at high risk 12 12 $182

In context: peer comparison

Among 1 peers in this city , average services per provider: 33. This provider delivers 10× the peer median.

Medicare Part D · 2023

Top prescriptions

CMS Part D Prescriber
Total claims
662
Patients
164
Total drug cost
$10,611
Drug Type Claims Patients Total cost
Omeprazole Generic 240 79 $3,945
Atorvastatin Calcium Generic 60 19 $1,673
Gavilyte-G (Peg3350/Sod Sulf,bicarb,cl/Kcl) Brand 54 53 $766
Pantoprazole Sodium Generic 44 13 $1,033
Losartan Potassium Generic 42 0 $520
Famotidine Generic 27 0 $518
Alendronate Sodium Generic 26 0 $199
Hydrochlorothiazide Generic 23 0 $173
Lisinopril Generic 23 0 $112
Triamterene-Hydrochlorothiazid (Triamterene/Hydrochlorothiazid) Brand 23 0 $400

Hospital affiliations

CMS Hospital Compare

Frequently asked questions

Auto-generated from federal data
What is Dr. Mark Nitzberg's medical specialty?
Dr. Mark Nitzberg practices Gastroenterology Physician in Methuen, MA.
Where does Dr. Mark Nitzberg practice?
Dr. Mark Nitzberg practices at 38R Merrimack St., Methuen, MA 01844. Office phone: 9786811977.
What is Dr. Mark Nitzberg's NPI?
Dr. Mark Nitzberg's National Provider Identifier (NPI) is 1881652758, issued by NPPES.
Does Dr. Mark Nitzberg accept Medicare assignment?
Yes. Dr. Mark Nitzberg accepts Medicare assignment, meaning Medicare-allowed amounts are accepted as full payment for covered services.
What procedures does Dr. Mark Nitzberg commonly perform?
Top Medicare-reported procedures in 2023: New patient office or other outpatient visit (HCPCS 99203); Established patient office or other outpatient visit (HCPCS 99213); Biopsy of large bowel using a flexible endoscope (HCPCS 45380). Source: CMS Medicare Physician & Other Practitioners file.