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

William M Sullivan, MD

Individual provider Endocrinology, Diabetes & Metabolism Physician · NPI 1922107234

William M Sullivan, MD practises Endocrinology in Boston, Massachusetts. Graduated from Georgetown University School of Medicine in 1980, 46 years ago. Practices with Joslin Clinic Inc, a 54-clinician group, accepts Medicare assignment and offers telehealth. Licensed in Massachusetts.

Years since qualifying
46
Trained at
Georgetown University School of Medicine
Licensed in
MA
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.

Joslin Diabetes Center One Joslin Pl
Boston, MA 02215 Not confirmed with CMS for 14 years — call before visiting
Phone: (617) 732-2645
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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 72821 (MA)

Record details

NPI number1922107234
Entity typeIndividual (Type 1)
GenderMale
Credentials MD
Sole proprietorNo
NPI enumeratedSeptember 22, 2006
Last updated in NPPESNovember 28, 2011

Medicare enrollment

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

Medicare specialtyENDOCRINOLOGY
Medical schoolGEORGETOWN UNIVERSITY SCHOOL OF MEDICINE
Graduated 1980 (46 years in practice)
Group practice Joslin Clinic Inc — 54 clinicians
Accepts Medicare assignment Yes — accepts the Medicare-approved amount
TelehealthOffers telehealth services
Practice locations3 on file with Medicare

Medicare patients and services, 2024

From the CMS Medicare Physician & Other Practitioners file for calendar year 2024. It counts Original Medicare patients only, so a practice that mostly sees Medicare Advantage or privately insured patients looks smaller here than it is.

Medicare patients336
Services billed 1,086 a service is one billed item, such as a visit, a test or a procedure
Average patient age75

Dollar amounts are not shown. What Medicare pays a practice is gross billings, before staff, premises and tax and including the cost of any drugs it administers, so it is not what a clinician earns.

Practises at

Facilities the CMS Facility Affiliation file lists for this clinician.

Colleagues at Joslin Clinic Inc

Clinicians the CMS Doctors & Clinicians file lists under the same group practice. CMS counts 54 clinicians in the practice; 12 are shown here.

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