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

Dr. William G. Tsiaras, MD, PHD

Individual provider Internal Medicine Physician · NPI 1215255526

Dr. William G. Tsiaras, MD, PHD practises Dermatology in Boston, Massachusetts. Qualified in 2010, 16 years ago. Practices with Brigham and Womens Physicians Organization Inc, a 2,916-clinician group, accepts Medicare assignment and offers telehealth. Licensed in Massachusetts and Rhode Island.

Years since qualifying
16
Licensed in
MA, RI
In the registry since
2010
Specialties on file
3
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

221 Longwood Ave Brigham Dermatology Associates
Boston, MA 02115-5804 Not confirmed with CMS for 11 years — call before visiting
Phone: (617) 732-4918
Fax: (617) 582-6060
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Pin is approximate — placed at the ZIP-code centre, not the exact door.

Specialties & licences

Dermatology Physician (primary) Taxonomy 207N00000X · Licence 259741 (MA)
Internal Medicine Physician Taxonomy 207R00000X · Licence LP01895 (RI)
Dermatology Physician Taxonomy 207N00000X · Licence 247360 (MA)

Record details

NPI number1215255526
Entity typeIndividual (Type 1)
GenderMale
Credentials MD , PHD
Sole proprietorNo
NPI enumeratedMay 11, 2010
Last updated in NPPESMarch 19, 2015

Medicare enrollment

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

Medicare specialtyDERMATOLOGY
Medical schoolOTHER
Graduated 2010 (16 years in practice)
Group practice Brigham And Womens Physicians Organization Inc — 2916 clinicians
Accepts Medicare assignment Yes — accepts the Medicare-approved amount
TelehealthOffers telehealth services

Procedures

From CMS Care Compare, which counts the procedures a clinician billed to Original Medicare and Medicare Advantage over a recent 12-month period. CMS reports a fixed list of common procedures, so this is not everything the clinician does. Counts of 10 or fewer are given as a range, because CMS withholds small numbers.

Removal of tissue 154 times · 89th percentile
Removal of skin lesions 305 times · 82nd percentile
Skin biopsy 42 times · 68th percentile

The percentile compares how often this clinician performed the procedure with other clinicians who performed it, as CMS calculates it. It measures volume, not outcomes or skill.

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 patients342
Services billed 1,779 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 Brigham and Womens Physicians Organization Inc

Clinicians the CMS Doctors & Clinicians file lists under the same group practice. CMS counts 2916 clinicians in the practice; 12 are shown here.

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