Provider records sourced from NPPES (CMS National Plan & Provider Enumeration System). Data current as of August 10, 2026.
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Dr. Cliff O'Callahan, MD, PHD

Individual provider Family Medicine Physician · NPI 1811977663

Dr. Cliff O'Callahan, MD, PHD is a Family Medicine Physician in Middletown, Connecticut. Licensed in Connecticut. Registered with an NPI since 2006.

Licensed in
CT
In the registry since
2006
Specialties on file
2
What do these letters mean?
MD — Doctor of Medicine
A physician who completed allopathic medical school.
PHD — Doctor of Philosophy
A research doctorate. In healthcare it usually sits alongside a clinical licence.

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Practice location Address checks out

90 S Main St
Middletown, CT 06457-3649
Phone: (860) 344-6300
Fax: (860) 344-9249
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Pin is approximate — placed at the ZIP-code centre, not the exact door.

Specialties & licences

Pediatrics Physician (primary) Taxonomy 208000000X · Licence 040077 (CT)
Family Medicine Physician Taxonomy 207Q00000X · Licence 040077 (CT)

Record details

NPI number1811977663
Entity typeIndividual (Type 1)
GenderMale
Credentials MD , PHD
Sole proprietorNo
NPI enumeratedJanuary 18, 2006
Last updated in NPPESDecember 1, 2020
Certification dateDecember 1, 2020

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