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

Dr. John Mascarenhas, MD

Individual provider Hematology & Oncology Physician · NPI 1376719104

Dr. John Mascarenhas, MD practises Hematology in New York, New York. Graduated from New York Medical College in 2002, 24 years ago. Practices with Icahn School of Medicine at Mount Sinai, a 2,791-clinician group and accepts Medicare assignment. Licensed in New York.

Years since qualifying
24
Trained at
New York Medical College
Licensed in
NY
In the registry since
2008
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

1 Gustave L Levy Pl Box 1079
New York, NY 10029-6500 Not confirmed with CMS for 18 years — call before visiting
Phone: (212) 241-1948
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Pin is approximate — placed at the ZIP-code centre, not the exact door.

Specialties & licences

Hematology & Oncology Physician (primary) Taxonomy 207RH0003X · Licence 235966 (NY)

Record details

NPI number1376719104
Entity typeIndividual (Type 1)
GenderMale
Credentials MD
Sole proprietorYes
NPI enumeratedMay 1, 2008
Last updated in NPPESJuly 7, 2008

Medicare enrollment

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

Medicare specialtyHEMATOLOGY
Medical schoolNEW YORK MEDICAL COLLEGE
Graduated 2002 (24 years in practice)
Group practice Icahn School Of Medicine At Mount Sinai — 2791 clinicians
Accepts Medicare assignment Yes — accepts the Medicare-approved amount

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 patients197
Services billed 657 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.

Consulting Fee $55,010 21 payments
Travel and Lodging $5,989 3 payments · travel or lodging paid or reimbursed, such as to attend a conference
Honoraria $2,400 1 payment
Food and Beverage $1,795 28 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. Those with a page here are linked.

Colleagues at Icahn School of Medicine at Mount Sinai

Clinicians the CMS Doctors & Clinicians file lists under the same group practice. CMS counts 2791 clinicians in the practice; 12 are shown here.

Other providers in New York