Mackenzie Breen
Physician Assistant β’ Boston, MA
800 Washington St
Boston, MA 021111552
This profile restates public CMS/NPPES data; T-MedInfo gives no medical advice — consult a licensed professional, and call 911 for emergencies.
Practice Location & Contact Primary Location
800 Washington St
Boston, MA 021111552
Matched by practice address or phone in NPPES. A shared address or phone does not confirm that this clinician works there.
What Public CMS Data Show
Physician Assistant: NPPES taxonomy is a reported classification, not proof of board certification.
Industry payments (Open Payments)
No Open Payments records are listed for this clinician for 2021β2025.
NPI first issued
2025
The year this clinician's National Provider Identifier (NPI) was issued. An NPI is a unique 10-digit ID that US health care providers use for billing.
What this does not show: NPI first issued
NPIs have been issued only since 2005, so this year is not necessarily when the clinician started practicing.
Source: CMS NPPES NPI Registry.
Medicare assignment not listed
CMS data do not show whether this clinician accepts Medicare assignment. This does not mean they do not accept Medicare. Ask the office.
Medicare assignment applies to Original Medicare. It does not tell you whether the clinician is in a Medicare Advantage plan's network, accepts other insurance, or is taking new patients.
Source: CMS Doctors and Clinicians; Medicare.gov, βDoes your provider accept Medicare as full payment?β
No telehealth indicator
CMS shows this indicator only when recent Medicare claims include telehealth services. The clinician may still offer telehealth; ask the office.
Source: CMS, Telehealth Indicator on Medicare Care Compare (fact sheet, January 2023); CMS Doctors and Clinicians.
Compared with the same specialty in Boston and Massachusetts
1,694 active clinicians are listed under Physician Assistant with a practice address in Boston, MA (4,768 in Massachusetts).
Addresses are self-reported to NPPES and may be out of date.
Telehealth indicator in Boston
15.1% of these 1,694 clinicians have the CMS telehealth indicator.
56.2% of these 1,694 clinicians are listed by CMS as accepting Medicare assignment.
Sources: CMS Doctors and Clinicians, CMS NPPES NPI Registry. Specialty names follow the NUCC Health Care Provider Taxonomy.
Text: T-MedInfo Β· Report an error.
Specialties & License Numbers Reported to NPPES
Self-certified to NPPES: 2026-10-27NUCC Taxonomy Code: 363A00000X
A physician assistant is a person who has successfully completed an accredited education program for physician assistant, is licensed by the state and is practicing within the scope of that license. Physician assistants are formally trained to perform many of the routine, time-consuming tasks a physician can do. In some states, they may prescribe medications. They take medical histories, perform physical exams, order lab tests and x-rays, and give inoculations. Most states require that they work under the supervision of a physician.
Clinicians Sharing This Practice Address or Phone
Clinicians sharing this NPPES address, phone or fax; a shared contact does not mean they work together.
Orthopaedic Surgery
Doctor of Medicine (M.D.)
Internal Medicine
Doctor of Medicine (M.D.)
Internal Medicine
Doctor of Medicine (M.D.)
Internal Medicine - Nephrology
Doctor of Medicine (M.D.)
Internal Medicine - Pulmonary Disease
Doctor of Medicine (M.D.)
Internal Medicine
Doctor of Medicine (M.D.)
Career & Practice History Timeline
Changes recorded in monthly NPPES data files: addresses, names, credentials, specialties and NPI status
Registered at 800 WASHINGTON ST, BOSTON, MA 021111552 (Tel: 6176365000)
Physician Assistant (license number reported to NPPES: MA PA102813)
NPI status registered as active in NPPES database
Registered at 240 E HURON ST STE 1-200, CHICAGO, IL 606112909 (Tel: 7743306288)
Registered at 240 E HURON ST STE 1-200, CHICAGO, IL 606112909 (Tel: 3125031851)
Recorded as MACKENZIE BREEN
Student in an Organized Health Care Education/Training Program
First registered as active Individual Practitioner in NPPES Database.
NPI Administrative Meta
Other Physician Assistants in Boston
- Judith Phillips, PA-C
- Taylor Krozy, PA-C
- Amanda Grasso, PA-C
- Brenna Hobin, PA-C
- Schaillee Butler, PA
- Dr. Noelle Lawler, MD
Mailing Address
240 E Huron St Ste 1-200
Chicago, IL 606112909
Phone: 3125031851