NPPES file of Aug 9, 2026

Jonathan Eisen, M.D.

Internal Medicine Physician · Boston, MA

Jonathan Eisen, M.D. is an internal medicine physician with a practice address in Boston, Massachusetts, and NPI 1396126686, issued on Jun 12, 2015. Check the license (Massachusetts 263228, as entered in NPPES) on the Massachusetts Board of Registration in Medicine; the Medicare figures below come from public CMS files.

Record from CMS NPPES, file of Aug 9, 2026 · Medicare files 2024 · method · Verify with CMS →

NPPES recordNPPES file of Aug 9, 2026
1396126686
Name
Jonathan Eisen
Credential
M.D.
Primary taxonomy
Internal Medicine Physician 207R00000X
License number
263228 MA
Self-reported in NPPES; status is on the state search
Practice location
800 Washington St, Boston, MA 02111
Phone
(617) 636-5000
Enumerated
Jun 12, 2015
Record last updated
Jan 15, 2026
Medicare enrollment
Enrolled (PECOS I20180517000398); accepts Medicare assignment
Entity
Type 1 · individual
Public record from CMS NPPES (open it on the CMS NPI Registry). Enrollment, assignment, school and telehealth: CMS Doctors and Clinicians file, Aug 2026. A record is not a license: verify it with the state board.
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Also registered at 800 Washington St

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

  1. Jeffrey Aalberg, MD, MPHSurgery Physician1326788027
  2. Omer Abbak, PHARMDPharmacist1114500337
  3. Aya Abdelnaser, MDStudent in an Organized Health Care Education/Training Program1770425373
  4. Marie Elise Abi Antoun, MDObstetrics & Gynecology Physician1356042626
  5. Ahmad AboalfarajSurgery Physician1538517651
  6. Tala Abu Samaan, MDStudent in an Organized Health Care Education/Training Program1376386250

Verify Jonathan Eisen 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 263228
    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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99% fewer Medicare Part D claims than the average internal medicine physician in 2024

19 Medicare Part D claims, against an average of 3,176 among the 108,855 providers of this specialty who prescribed in Part D.

  1. Jonathan Eisen19
  2. Specialty average3,176

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.

Bills Medicare through one group practice

  1. Massachusetts General Physicians Organization IncBoston, MA

Source: CMS Doctors and Clinicians National Downloadable File (the group practices a clinician bills Medicare through) (data.cms.gov).

Jonathan Eisen among 6,825 internal medicine physician records in Massachusetts

Jonathan Eisen, M.D. is one of 6,825 internal medicine physician records with a practice address in Massachusetts. 75% of them appear in a Medicare file (Part D prescribing, MIPS, Open Payments or Medicare group billing); this one does. Its NPI, issued in 2015, is newer than 74% of them.

  • NPI issued2015 · 74% of these records are older, 23% newer
  • In a Medicare fileYes · 75% of these records are
  • In the CMS Doctors and Clinicians fileYes · 60% of these records are
  • Graduated2015 · median 2004 among the 4,103 with a school on file
  • Record last updated2026 · 64% of these records were not updated in five years or more

Source: CMS NPPES, file of Aug 9, 2026, every record with primary taxonomy 207R00000X and a Massachusetts practice address; Medicare files: CMS Part D Prescribers 2024, MIPS 2023, Open Payments 2024, Doctors and Clinicians (data.cms.gov).

2,320 internal medicine physician records list a practice address in Boston

They are 2,320 of the 41,865 NPPES records with a practice address in Boston, and 6,825 internal medicine physician records in Massachusetts.

The 8 internal medicine physician records with the nearest ZIP codes

  1. Dineli Ahearn, M.D.Boston, MA 021111528015922
  2. Ethan Balk, M.D.Boston, MA 021111831136571
  3. Jeanine Carlson, M.D.Boston, MA 021111588603013
  4. Peter Castaldi, M.D.Boston, MA 021111902891062
  5. Daniel Chandler, M.D.Boston, MA 021111760440168
  6. Wambui Chege, M.D.Boston, MA 021111275571549
  7. Kevin Chin, MDBoston, MA 021111568430593
  8. Shira Doron, M.D.Boston, MA 021111831121359

Common questions

What is Jonathan Eisen, M.D.'s NPI number?

Jonathan Eisen, M.D.'s National Provider Identifier (NPI) is 1396126686, issued on Jun 12, 2015. An NPI identifies a provider in billing; it is not a license.

Where is Jonathan Eisen, M.D. located?

The NPPES record lists a practice address at 800 Washington St, Boston, MA, 02111. Phone: (617) 636-5000. Providers update this record themselves, so call before visiting.

How can I verify Jonathan Eisen, M.D.'s license?

NPPES lists Massachusetts license number 263228, 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 Jonathan Eisen, M.D. prescribe under Medicare Part D?

In 2024, Jonathan Eisen, M.D. had 19 Medicare Part D claims; the average among internal medicine physician prescribers was 3,176. 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.