Mark C. Poznansky, MD PHD
Internal Medicine Physician · Boston, MA
Mark C. Poznansky, MD PHD is an internal medicine physician with a practice address in Boston, Massachusetts, and NPI 1265509889, issued on Nov 29, 2006. Check the license (Massachusetts 157686, as entered in NPPES) on the Massachusetts Board of Registration in Medicine; the Medicare figures below come from public CMS files.
- Name
- Mark C. Poznansky
- Credential
- MD PHD
- Primary taxonomy
- Internal Medicine Physician 207R00000X
- License number
- 157686 MA
Self-reported in NPPES; status is on the state search - Practice location
- Infectious Disease Associates, Boston, MA 02114
- Phone
- (617) 726-3906
- Enumerated
- Nov 29, 2006
- Record last updated
- Oct 29, 2007 (not updated in 19 years: call before relying on the address or phone)
- Medicaid ID
- 3190765 MA
- Medicare enrollment
- Enrolled (PECOS I20040625000734); accepts Medicare assignment
- Entity
- Type 1 · individual
8 nearest internal medicine physician records → All 6,825 in Massachusetts → Look up another NPI →
Also registered at Infectious Disease Associates
A shared address usually means a shared clinic or building; it does not show who employs whom.
- Nesli Basgoz, MDInfectious Disease Physician1841265238
Verify Mark C. Poznansky in five checks
- 1IdentityNPI record in CMS NPPESNPI lookupConfirmed in NPPES
- 2LicenseActive license and public ordersMassachusetts Board of Registration in Medicine
Search for license 157686Check the board - 3Other statesLicenses and actions elsewhereDocInfo (FSMB)Not checked
- 4ExclusionsMedicare and Medicaid bansHHS-OIG exclusion listNot checked
- 5CertificationBoard certificationABMS AOA NCCPA AANPNot checked
Bills Medicare through 2 group practices
- Massachusetts General Physicians Organization IncBoston, MA
- The General Hospital CorporationBoston, MA
Source: CMS Doctors and Clinicians National Downloadable File (the group practices a clinician bills Medicare through) (data.cms.gov).
Mark C. Poznansky among 6,825 internal medicine physician records in Massachusetts
Mark C. Poznansky, MD PHD 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 2006, is newer than 12% of them.
- NPI issued2006 · 12% of these records are older, 54% newer
- In a Medicare fileYes · 75% of these records are
- In the CMS Doctors and Clinicians fileYes · 60% of these records are
- Graduated1985 · median 2004 among the 4,103 with a school on file
- Record last updated2007 · 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.
All 6,825 in Massachusetts → Every provider in Boston → Internal Medicine Physician nationwide →
The 8 internal medicine physician records with the nearest ZIP codes
- Jaime Chang, MDBoston, MA 021141205825197
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- James Evans, MDBoston, MA 021141215939533
- Nicolette Fontaine, MDBoston, MA 021141841287174
- Nancy Gagliano, MDBoston, MA 021141881680767
- Patricia Gibbons, MDBoston, MA 021141619967221
- Steven Hersch, MDBoston, MA 021141174512149
- Mira Kautzky, M.D.Boston, MA 021141972505402
Common questions
What is Mark C. Poznansky, MD PHD's NPI number?
Mark C. Poznansky, MD PHD's National Provider Identifier (NPI) is 1265509889, issued on Nov 29, 2006. An NPI identifies a provider in billing; it is not a license.
Where is Mark C. Poznansky, MD PHD located?
The NPPES record lists a practice address at Infectious Disease Associates, Boston, MA, 02114. Phone: (617) 726-3906. Providers update this record themselves, so call before visiting.
How can I verify Mark C. Poznansky, MD PHD's license?
NPPES lists Massachusetts license number 157686, 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. 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.