NPPES file of Aug 9, 2026

Douglas A. Janowski, M.D.

Gastroenterology Physician · Boston, MA

Douglas A. Janowski, M.D. is a gastroenterology physician with a practice address in Boston, Massachusetts, and NPI 1700803855, issued on Jul 16, 2006. Check the license (Massachusetts 203367, as entered in NPPES) on the Massachusetts Board of Registration in Medicine; the federal record below is the public data PlainDoctor holds for this provider.

Record from CMS NPPES, file of Aug 9, 2026 · method · Verify with CMS →

NPPES recordNPPES file of Aug 9, 2026
1700803855
Name
Douglas A. Janowski
Credential
M.D.
Primary taxonomy
Gastroenterology Physician 207RG0100X
License number
203367 MA
Self-reported in NPPES; status is on the state search
Practice location
750 Washington St, Boston, MA 02111
Phone
(617) 636-5000
Enumerated
Jul 16, 2006
Record last updated
Jul 8, 2007 (not updated in 19 years: call before relying on the address or phone)
Entity
Type 1 · individual
Public record from CMS NPPES (open it on the CMS NPI Registry). A record is not a license: verify it with the state board.
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8 nearest gastroenterology physician records → All 686 in Massachusetts → Look up another NPI →

Also registered at 750 Washington St

A shared address usually means a shared clinic or building; it does not show who employs whom.

  1. Maureen Abbott, NPAdult Health Nurse Practitioner1457591638
  2. Paul Abourjaily, PHARMDPharmacotherapy Pharmacist1255337044
  3. Lori Abrahamian, M.D.Anesthesiology Physician1528012192
  4. Mary Ahern, PMHCNS-BCPsychiatric/Mental Health Clinical Nurse Specialist1619137742
  5. Ghada Al Mubarak, M.D.Surgery Physician1407034911
  6. Abeer Al-Naqbi, M.D.Obstetrics & Gynecology Physician1043426919

Verify Douglas A. Janowski in five checks

  1. 1IdentityNPI record in CMS NPPESNPI lookupConfirmed in NPPES
  2. 2LicenseActive license and public ordersMassachusetts Board of Registration in Medicine
    Search for license 203367    Check the board
  3. 3Other statesLicenses and actions elsewhereDocInfo (FSMB)Not checked
  4. 4ExclusionsMedicare and Medicaid bansHHS-OIG exclusion listNot checked
  5. 5CertificationBoard certificationABMS AOA NCCPA AANPNot checked
Open the Massachusetts license search

PlainDoctor does not match the HHS-OIG exclusion list to individual records: most entries carry no NPI. Search the OIG exclusion list by name.

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Douglas A. Janowski among 686 gastroenterology physician records in Massachusetts

Douglas A. Janowski, 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 not. Its NPI, issued in 2006, is newer than 14% of them.

  • NPI issued2006 · 14% of these records are older, 49% newer
  • In a Medicare fileNo · 80% of these records are
  • In the CMS Doctors and Clinicians fileNo · 72% of these records are
  • Record last updated2007 · 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. No Medicare prescribing, quality score, industry payment or hospital affiliation is published for this NPI.

All 686 in Massachusetts → Every provider in Boston → Gastroenterology Physician nationwide →

The 8 gastroenterology physician records with the nearest ZIP codes

  1. Harmony Allison, MDBoston, MA 021111245240704
  2. Peter Bonis, M.D.Boston, MA 021111548462807
  3. Aaron Dickstein, M.D.Boston, MA 021111003059239
  4. Daria Homenko, M.D.Boston, MA 021111891958385
  5. Allen Hwang, M.D., M.S.C.E.Boston, MA 021111558532689
  6. Sushrut Jangi, MDBoston, MA 021111376770115
  7. Raffi Karagozian, MDBoston, MA 021111356394233
  8. Young-Mee Lee, MDBoston, MA 021111679681399

Common questions

What is Douglas A. Janowski, M.D.'s NPI number?

Douglas A. Janowski, M.D.'s National Provider Identifier (NPI) is 1700803855, issued on Jul 16, 2006. An NPI identifies a provider in billing; it is not a license.

Where is Douglas A. Janowski, M.D. located?

The NPPES record lists a practice address at 750 Washington St, Boston, MA, 02111. Phone: (617) 636-5000. Providers update this record themselves, so call before visiting.

How can I verify Douglas A. Janowski, M.D.'s license?

NPPES lists Massachusetts license number 203367, 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.

Source: CMS National Plan and Provider Enumeration System (NPPES), file of Aug 9, 2026 (NPPES files on CMS.gov); NUCC Health Care Provider Taxonomy. An NPI identifies who bills; it is not a license.

Written with AI tools from the named public files; every figure is computed from those files (how it is made).

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.