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

Jonathan Mazer, MD

Individual provider Student in an Organized Health Care Education/Training Program · NPI 1902288194

Jonathan Mazer, MD practises Anesthesiology in Boston, Massachusetts. Qualified in 2015, 11 years ago. Practices with Rwjbh Observation Associates LLC, a 971-clinician group and accepts Medicare assignment. Licensed in Massachusetts and New Jersey.

Years since qualifying
11
Licensed in
MA, NJ
In the registry since
2015
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

Student / training record This NPI belongs to someone enrolled in a health care training programme. It carries no licence and no practice of its own, so no address or phone number is published for it.

Boston, MA

No coordinates on file. Search this address in Google Maps

Specialties & licences

Anesthesiology Physician (primary) Taxonomy 207L00000X · Licence 25MA10401500 (NJ)
Student in an Organized Health Care Education/Training Program Taxonomy 390200000X · Licence 263741 (MA)

Record details

NPI number1902288194
Entity typeIndividual (Type 1)
GenderMale
Credentials MD
Sole proprietorNo
NPI enumeratedJune 24, 2015
Last updated in NPPESMay 22, 2019

Medicare enrollment

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

Medicare specialtyANESTHESIOLOGY
Medical schoolOTHER
Graduated 2015 (11 years in practice)
Group practice Rwjbh Observation Associates Llc — 971 clinicians
Accepts Medicare assignment Yes — accepts the Medicare-approved amount
Practice locations4 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 patients243
Services billed 263 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.

Payments from drug and device companies, 2025

Drug and device makers are required by federal law (the Physician Payments Sunshine Act) to report what they pay or give to clinicians, and CMS publishes the reports as Open Payments. This is the 2025 program year. A report is a record of a payment, not an allegation of anything, and many are small items such as meals. Only general payments are listed here; research payments and ownership or investment interests are reported separately by CMS and are not shown.

Food and Beverage $36 2 payments · a meal or drink at a meeting or visit, not a fee

Each amount is the sum of what companies reported for that kind of payment in 2025, rounded to the dollar. Not all of it is income to the clinician: a meal is not a fee, a charitable contribution goes to a charity, and a royalty or an acquisition payment is not a salary.

Check a report, or dispute one, at the source in CMS’s own tool, Open Payments. Corrections go through CMS’s dispute process. This site removes a home address on request and asks for no proof, because that is privacy; it will not remove an accurate payment report on request, because that is a statutory public disclosure.

Practises at

Facilities the CMS Facility Affiliation file lists for this clinician.

Colleagues at Rwjbh Observation Associates LLC

Clinicians the CMS Doctors & Clinicians file lists under the same group practice. CMS counts 971 clinicians in the practice; 12 are shown here.

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