Mark C. Nitzberg, M.D.
Gastroenterology Physician · Methuen, MA
Mark C. Nitzberg, M.D. is a gastroenterology physician with a practice address in Methuen, Massachusetts, and NPI 1881652758, issued on May 2, 2006. Check the license (Massachusetts 74584, as entered in NPPES) on the Massachusetts Board of Registration in Medicine; the Medicare figures below come from public CMS files.
- Name
- Mark C. Nitzberg
- Credential
- M.D.
- Primary taxonomy
- Gastroenterology Physician 207RG0100X
- License number
- 74584 MA
Self-reported in NPPES; status is on the state search - Practice location
- 38R Merrimack St., Methuen, MA 01844
- Phone
- (978) 681-1977
- Enumerated
- May 2, 2006
- Record last updated
- Nov 16, 2017 (not updated in 9 years: call before relying on the address or phone)
- Fax
- (978) 686-8918
- Medicare enrollment
- Enrolled (PECOS I20160503000287); accepts Medicare assignment
- Medical or professional school
- University Of Massachusetts Medical School, 1989
- Telehealth
- Offers telehealth (CMS)
- Entity
- Type 1 · individual
8 nearest gastroenterology physician records → All 686 in Massachusetts → Look up another NPI →
Verify Mark C. Nitzberg in five checks
- 1IdentityNPI record in CMS NPPESNPI lookupConfirmed in NPPES
- 2LicenseActive license and public ordersMassachusetts Board of Registration in Medicine
Search for license 74584Check the board - 3Other statesLicenses and actions elsewhereDocInfo (FSMB)Not checked
- 4ExclusionsMedicare and Medicaid bansHHS-OIG exclusion listNot checked
- 5CertificationBoard certificationABMS AOA NCCPA AANPNot checked
25% more Medicare Part D claims than the average gastroenterology physician in 2024
1,015 Medicare Part D claims for 200 beneficiaries, against an average of 811 among the 16,445 providers of this specialty who prescribed in Part D.
Most prescribed
- Omeprazole222 claims
- Atorvastatin Calcium66 claims
- Pantoprazole Sodium54 claims
- Losartan Potassium35 claims
- Gavilyte-G33 claims
- Triamterene-Hydrochlorothiazid29 claims
Source: CMS Medicare Part D Prescribers by Provider and Drug, 2024 (data.cms.gov). Part D covers prescriptions for Medicare patients only; drugs with fewer than 11 claims are not published.
Mark C. Nitzberg among 686 gastroenterology physician records in Massachusetts
Mark C. Nitzberg, M.D. is one of 686 gastroenterology physician records with a practice address in Massachusetts. 80% of them appear in a Medicare file (Part D prescribing, MIPS, Open Payments or Medicare group billing); this one does. Its NPI, issued in 2006, is newer than 14% of them.
- NPI issued2006 · 14% of these records are older, 49% newer
- In a Medicare fileYes · 80% of these records are
- In the CMS Doctors and Clinicians fileYes · 72% of these records are
- Graduated1989 · median 2004 among the 491 with a school on file
- Record last updated2017 · 66% of these records were not updated in five years or more
Source: CMS NPPES, file of Aug 9, 2026, every record with primary taxonomy 207RG0100X and a Massachusetts practice address; Medicare files: CMS Part D Prescribers 2024, MIPS 2023, Open Payments 2024, Doctors and Clinicians (data.cms.gov).
Gastroenterology Physician providers in Massachusetts
There are 686 gastroenterology physician records in Massachusetts.
All 686 in Massachusetts → Every provider in Methuen → Gastroenterology Physician nationwide →
The 8 gastroenterology physician records with the nearest ZIP codes
- Richard Sawyer, MDMethuen, MA 018441093794042
- Thomas Fazio, M.D.Lawrence, MA 018431902800832
- Drew Niccolini, M.D.Lawrence, MA 018431639174410
- Franklin Marinelli, MDLowell, MA 018511780676155
- Winnie Szeto, MDLowell, MA 018511588899504
- Richard Tilson, MDLowell, MA 018511346336831
- Ali Hashmi, M.B.B.SHaverhill, MA 018301336473172
- Jason Hemming, M.D.Haverhill, MA 018301184712010
Common questions
What is Mark C. Nitzberg, M.D.'s NPI number?
Mark C. Nitzberg, M.D.'s National Provider Identifier (NPI) is 1881652758, issued on May 2, 2006. An NPI identifies a provider in billing; it is not a license.
Where is Mark C. Nitzberg, M.D. located?
The NPPES record lists a practice address at 38R Merrimack St., Methuen, MA, 01844. Phone: (978) 681-1977. Providers update this record themselves, so call before visiting.
How can I verify Mark C. Nitzberg, M.D.'s license?
NPPES lists Massachusetts license number 74584, as entered by the provider. Search the Massachusetts Board of Registration in Medicine at https://findmydoctor.mass.gov/. The NPPES record confirms identity only; the state search shows license status, expiration and public orders.
How much does Mark C. Nitzberg, M.D. prescribe under Medicare Part D?
In 2024, Mark C. Nitzberg, M.D. had 1,015 Medicare Part D claims for 200 beneficiaries; the average among gastroenterology physician prescribers was 811. Part D covers Medicare prescriptions only.
Source: CMS National Plan and Provider Enumeration System (NPPES), file of Aug 9, 2026 (NPPES files on CMS.gov); NUCC Health Care Provider Taxonomy. Medicare files from data.cms.gov. An NPI identifies who bills; it is not a license.
Figures on PlainDoctor are read from the federal files each page names (CMS NPPES, Medicare Part D, MIPS, Open Payments; the HHS-OIG exclusion list only as counts) and from Census population estimates, with the file date shown beside them. See our editorial standards & corrections policy, the methodology behind these numbers, or report a data error. Data current as of Aug 9, 2026.