Provider records sourced from NPPES (CMS National Plan & Provider Enumeration System). Data current as of August 10, 2026.

John B Constantine, MD

Individual provider Specialist · NPI 1437157765

John B Constantine, MD is a Specialist in Chelmsford, Massachusetts. Licensed in Massachusetts. Registered with an NPI since 2005.

Licensed in
MA
In the registry since
2005
Specialties on file
2
What do these letters mean?
MD — Doctor of Medicine
A physician who completed allopathic medical school.

See every abbreviation used in this directory →

Practice location Address checks out

19 Village Sq
Chelmsford, MA 01824-2712
Phone: (978) 256-5600
Fax: (978) 703-0250
Show map & directions

Pin is approximate — placed at the ZIP-code centre, not the exact door.

Specialties & licences

Ophthalmology Physician (primary) Taxonomy 207W00000X · Licence 71751 (MA)
Specialist Taxonomy 174400000X · Licence 71751 (MA)

Record details

NPI number1437157765
Entity typeIndividual (Type 1)
GenderMale
Credentials MD
Sole proprietorNo
NPI enumeratedJuly 11, 2005
Last updated in NPPESSeptember 29, 2011
Mailing address19 Village Sq, Chelmsford, MA 01824-2712

Other providers in Chelmsford