Provider records sourced from NPPES (CMS National Plan & Provider Enumeration System). Data current as of October 4, 2026.
NPIDirectory

Dr. Daniel Alexander Leffler, MD

Individual provider Internal Medicine Physician · NPI 1144368697

Dr. Daniel Alexander Leffler, MD practises Gastroenterology in Boston, Massachusetts. Qualified in 2002, 24 years ago. Practices with Harvard Medical Faculty Phys at Beth Israel Deaconess Med Ctr Inc, a 1,676-clinician group, accepts Medicare assignment and offers telehealth. Licensed in Massachusetts.

Years since qualifying
24
Licensed in
MA
In the registry since
2007
Specialties on file
2
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

330 Brookline Ave Dana 501
Boston, MA 02215-5400 Not confirmed with CMS for 15 years — call before visiting
Phone: (617) 667-2136
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Pin is approximate — placed at the ZIP-code centre, not the exact door.

Specialties & licences

Gastroenterology Physician (primary) Taxonomy 207RG0100X · Licence 223242 (MA)
Internal Medicine Physician Taxonomy 207R00000X · Licence 223242 (MA)

Record details

NPI number1144368697
Entity typeIndividual (Type 1)
GenderMale
Credentials MD
Sole proprietorNo
NPI enumeratedFebruary 4, 2007
Last updated in NPPESApril 13, 2011

Medicare enrollment

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

Medicare specialtyGASTROENTEROLOGY
Also practisesINTERNAL MEDICINE
Medical schoolOTHER
Graduated 2002 (24 years in practice)
Group practice Harvard Medical Faculty Phys At Beth Israel Deaconess Med Ctr Inc — 1676 clinicians
Accepts Medicare assignment Yes — accepts the Medicare-approved amount
TelehealthOffers telehealth services
Practice locations2 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 patients22
Services billed 33 a service is one billed item, such as a visit, a test or a procedure
Average patient age71

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 Harvard Medical Faculty Phys at Beth Israel Deaconess Med Ctr Inc

Clinicians the CMS Doctors & Clinicians file lists under the same group practice. CMS counts 1676 clinicians in the practice; 12 are shown here.

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