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

Individual provider Endocrinology, Diabetes & Metabolism Physician · NPI 1689693327

Dr. John Leff, MD is an Endocrinology, Diabetes & Metabolism Physician in Brooklyn, New York. Licensed in New York. Registered with an NPI since 2006.

Licensed in
NY
In the registry since
2006
What do these letters mean?
MD — Doctor of Medicine
A physician who completed allopathic medical school.

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Practice location Partly verified

Some contact details are missing from the federal record.

Lutheran Medical Center 150 55th St
Brooklyn, NY 11220
Phone: (718) 630-7369
Fax: (718) 630-6286
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Pin is approximate — placed at the ZIP-code centre, not the exact door.

Specialties & licences

Endocrinology, Diabetes & Metabolism Physician (primary) Taxonomy 207RE0101X · Licence 143472 (NY)

Record details

NPI number1689693327
Entity typeIndividual (Type 1)
GenderMale
Credentials MD
Sole proprietorNo
NPI enumeratedJuly 19, 2006
Last updated in NPPESJanuary 17, 2012

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