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

Thomas Neil O'Callaghan, MD

Individual provider Internal Medicine Physician · NPI 1265926331

Thomas Neil O'Callaghan, MD is an Internal Medicine in Ann Arbor, Michigan. Graduated from University of Michigan Medical School in 2022, 4 years ago. Practices with Regents of the University of Michigan, a 3,271-clinician group and accepts Medicare assignment. Licensed in Michigan.

Years since qualifying
4
Trained at
University of Michigan Medical School
Licensed in
MI
In the registry since
2018
What do these letters mean?
MD — Doctor of Medicine
A physician who completed allopathic medical school.

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Practice location Address checks out

1500 E Medical Center Dr
Ann Arbor, MI 48109-5000
Phone: (734) 936-4000
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Pin is approximate — placed at the ZIP-code centre, not the exact door.

Specialties & licences

Internal Medicine Physician (primary) Taxonomy 207R00000X · Licence 4301507148 (MI)

Record details

NPI number1265926331
Entity typeIndividual (Type 1)
GenderMale
Credentials MD
Sole proprietorNo
NPI enumeratedJune 21, 2018
Last updated in NPPESJuly 25, 2022
Certification dateJuly 25, 2022

Medicare enrollment

From the CMS Doctors & Clinicians file — this clinician is enrolled in Medicare.

Medicare specialtyINTERNAL MEDICINE
Medical schoolUNIVERSITY OF MICHIGAN MEDICAL SCHOOL
Graduated 2022 (4 years in practice)
Group practice Regents Of The University Of Michigan — 3271 clinicians
Accepts Medicare assignment Yes — accepts the Medicare-approved amount
Practice locations14 on file with Medicare

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