
Richard M. Gewanter, MD
Radiation Oncologist
Clinical Expertise
Prostate Cancer; Breast Cancer; Lung Cancer; Bladder Cancer; Head & Neck Cancers; Intensity-Modulated Radiation Therapy; High-Dose-Rate Brachytherapy
New Patient Appointments
Scheduling a visit is easy. Click below or call us to get started.
- 646-497-9068 Prostate
- 631-623-4269 All others
Dr. Gewanter accepts the following list of insurance providers. Select your insurance provider to see more details.
Memorial Sloan Kettering is an in-network provider with Aetna HMO, POS, and PPO plans. Aetna does not include us in any of the plans you can purchase through the insurance exchanges or through Medicare. Please ask your insurance if you need a one-time referral. MSK has an agreement with the Aetna Transplant Program for all Aetna's commercial products.
Memorial Sloan Kettering is a designated Blue Distinction Center for bone marrow transplant and CAR-T.
We understand that there may be many complexities involved with insurance coverage purchased through the health exchange network of the Affordable Care Act. We’re here to help. If you have questions about how your care will be covered by an insurance provider, or need help navigating a change in coverage, please call us at 646-227-3378; if you are not a resident of New York, you can call us at 866-248-1274. Our team is here to listen to your concerns and assist you in any way we can. We want our care to be as accessible and affordable for as many people as possible.
Memorial Sloan Kettering is an in-network provider with CIGNA's HMO, POS, and PPO plans. CIGNA does not include us in any of the plans you can buy through the insurance exchanges.
- If you are a New York State resident: Please ask your insurance if you need a one-time referral.
- If you live outside of New York State: Please ask your insurance if you have in-network access to Memorial Sloan Kettering.
Memorial Sloan Kettering is an in-network provider with EmblemHealth’s PPO, EPO, POS, HMO plans. EmblemHealth includes GHI, HIP, Vytra, and ConnecticCare (in NYS Only). You must bring a referral from your Emblem primary care doctor to your first appointment. In-network participation exceptions include:
- Emblem’s HIP Commercial Millennium, Select Care and Enhanced Care Prime networks is not in-network with Memorial Sloan Kettering.
- Please call Emblem to confirm if your specific plan is in-network.
For information regarding Memorial Sloan Kettering’s participation with Emblem’s Medicare Advantage Plans, please refer to the Medicare & Medicaid page
Memorial Sloan Kettering is an in-network provider with Empire Blue Cross Blue Shield (Wellpoint) of New York Indemnity, HMO, EPO, PPO, POS and Medicare Advantage plans, with the following exceptions:
- Empire Blue Cross Blue Shield does not include us in any of the plans you can buy through the insurance exchanges.
- Please call Empire BCBS to confirm if your specific plan is in-network with Memorial Sloan Kettering.
Memorial Sloan Kettering is an in-network provider with HealthFirst’s commercial products; these commercial products are not purchased on the insurance exchanges.
Memorial Sloan Kettering is an in-network provider with HealthSmart’s Accel, HSPC, and HPO networks.
For our NJ locations, Memorial Sloan Kettering is an in-network provider with most Horizon Blue Cross Blue Shield of New Jersey plans for individuals, families, and small businesses. Horizon members with Blue Card Access (there would be a suitcase logo on the front of the card) may have access to our NY locations. Please call Horizon to confirm if your plan is in-network in NY.
Memorial Sloan Kettering is a designated Center of Excellence by Humana.
Memorial Sloan Kettering is a designated Center of Excellence by Interlink Health Services.
Memorial Sloan Kettering is a designated Center of Excellence by Lifetrac.
Memorial Sloan Kettering is an in-network provider for all MagnaCare health plans except those products you can buy through the insurance exchanges.
For information about Medicare and Medicaid, please visit this page
Memorial Sloan Kettering is an in-network provider with some Multiplan/Beech Street/PHCS plans. Contact your insurance carrier to find out if your plan provides in-network access to Memorial Sloan Kettering.
Memorial Sloan Kettering is a designated Center of Excellence by Multiplan.
If you are covered by more than one insurance plan, you will want to determine your benefits from both plans. First, you need to determine which one is your primary insurance provider by contacting your employee benefits office or your insurance carriers. After you find out which is your primary insurance provider, you should then contact your insurance carrier to determine if you have access to Memorial Sloan Kettering.
Memorial Sloan Kettering is an in-network provider with some MVP plans. Contact your insurance carrier to find out if your plan provides in-network access to Memorial Sloan Kettering.
Memorial Sloan Kettering is an in-network provider for New York State employees who have enrolled in UnitedHealthcare's Cancer Resource Services. If you have the Empire Plan, you should call Cancer Resources Services at 866-936-6002 to verify and enroll in this coverage.
Memorial Sloan Kettering is in-network with Oscar’s Circle Plus Network, a part of its Small Group Broad line that is offered only to select small business groups. Oscar does not include Memorial Sloan Kettering as an in-network provider for any of its individual plans. Please confirm eligibility with your insurance carrier.
Most Blue Cross Blue Shield plans include Memorial Sloan Kettering as an in-network provider. Contact your insurance company to confirm if Memorial Sloan Kettering is in-network.
We have agreements with several insurance companies that may provide additional coverage for cancer patients. These benefit programs include:
- AXA Assistance USA
- Beech Street
- Integrated Health Plans
- National Health Administrators
- National Preferred Provider Network
- UnitedHealthcare's Cancer Resource Services
- United Resource Network
- Veterans Choice Program
Memorial Sloan Kettering is an in-network provider with Oxford’s Freedom and Liberty plans as well as the Metro Plan (which is only offered to small business groups and no longer offered as individual plans). Please confirm with your insurance if you need a one-time referral. Note: Oxford’s Medicare Managed Care plan — Secure Horizon — does not include Memorial Sloan Kettering as an in-network provider. Oxford does not include us in any of the plans you can buy through the insurance exchanges.
Memorial Sloan Kettering is an in-network provider with the World Trade Center Health Program.
Memorial Sloan Kettering is an in-network provider with QualCare's PPO and HMO/POS network.
Memorial Sloan Kettering is a designated Center of Excellence by Specialty Care Management.
Hospital and physician services may be covered by TRICARE. Please call your TRICARE plan to confirm coverage at Memorial Sloan Kettering.
Memorial Sloan Kettering is an in-network provider with UnitedHealthCare's HMO, POS, and PPO plans. Please confirm with your insurance if a one-time referral is needed.
UnitedHealthCare's Medicare Managed Care plan does not include Memorial Sloan Kettering as an in-network provider.
United does not include us in any of the plans you can buy through the insurance exchanges.
Memorial Sloan Kettering is a designated Center of Excellence by UnitedHealthcare.
Contact and Location
- 516-559-1526 Office Phone
- Speaks English
- Memorial Sloan Kettering Nassau Uniondale, NY
- New York City

Memorial Sloan Kettering has locations throughout New York City, Long Island, New Jersey, and Westchester. These locations offer many services, including screening, chemotherapy, and medical testing.
See all locationsAbout Me
Education
MD, Albert Einstein College of Medicine
Residencies
Radiation Oncology - New York Presbyterian/Columbia University Medical Center
Board Certifications
Radiation Oncology
I am a radiation oncologist who sees patients at Memorial Sloan Kettering Nassau, on Long Island. I also see patients at Memorial Hospital in Manhattan. I treat a wide variety of cancer types, including prostate cancer, bladder cancer, lung cancer, and breast cancer. I have been practicing for 14 years.
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I was drawn to a career in radiation oncology while I was in medical school. I was impressed by how radiation oncologists combined biology, technology, and imaging to deliver targeted treatment for people with cancer. At the same time, I felt a calling to this field because of the opportunity to counsel and guide people through one of the most difficult periods in their lives.
As the field of radiation oncology has advanced, I have found it truly gratifying to be able to deliver more effective treatments with fewer side effects. These advances — such as stereotactic radiosurgery and stereotactic body radiation —allow us to greatly reduce treatment times. Patients used to spend eight to nine weeks on a typical radiation course, but with the latest technologies, they can now often complete their treatments in three to five days.
People who come for their first radiation appointment are often fearful, as there can be many unknowns: How will treatment affect quality of life? How will it affect loved ones? They also want to feel confident that they are making the right treatment choices but often feel overwhelmed by the information available on the internet, or from well-meaning friends. I try to help my patients understand all options. If we as a patient-clinician team decide radiation is the best option, I explain how we will achieve their treatment goals. I make it a priority to develop a bond of trust from the beginning so that my patients can feel confident and reassured.
In addition to my clinical work, I am a member of the prostate cancer research team in MSK’s Department of Radiation Oncology. I have also served as an expert panel member on the American College of Radiology’s Appropriateness Criteria Committee for Lung Cancer.
I make it a priority to develop a bond of trust from the beginning so that my patients can feel confident and reassured.
-Dr. Gewanter
Awards and Honors
- Castle Connolly Newsday Top Doctors on Long Island (2010-2016)
- UJA-Federation of New York, Long Island South Shore Healthcare Professionals honoree (2016)
Colleagues
Doctors at Memorial Sloan Kettering work as teams, with specialists from all different areas. This allows us to consider all your needs together, and to give you the best possible care.
See all External Beam Radiotherapy Service, Regional Care Network doctors
Clinical Trials

Memorial Sloan Kettering's doctors and scientists are constantly developing new treatments for cancer. MSK is typically running hundreds of clinical trials at a given time.
You may be able to participate in a clinical trial even if you are new to MSK. Search our online directory to find trial information and see more about who can participate.
Search clinical trialsResearch and Publications
Visit PubMed for a full listing of Dr. Gewanter’s journal articles. Pubmed is an online index of research papers and other articles from the US National Library of Medicine and the National Institutes of Health.
See all on PubMedDisclosures
Doctors and faculty members often work with pharmaceutical, device, biotechnology, and life sciences companies, and other organizations outside of MSK, to find safe and effective cancer treatments, to improve patient care, and to educate the health care community.
MSK requires doctors and faculty members to report (“disclose”) the relationships and financial interests they have with external entities. As a commitment to transparency with our community, we make that information available to the public.
Richard M. Gewanter discloses the following relationships and financial interests:
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Pfizer, Inc.
Ownership / Equity Interests
If you’re a patient at MSK and would like more information about your doctor’s external relationships, please talk with your doctor.
The information published here is for a specific annual disclosure period. There may be differences between information on this and other public sites as a result of different reporting periods and/or the various ways relationships and financial interests are categorized by organizations that publish such data.
This page and data include information for a specific MSK annual disclosure period (January 1, 2020 through disclosure submission in spring 2021). This data reflects interests that may or may not still exist. This data is updated annually.
Learn more about MSK’s COI policies here. For questions regarding MSK’s COI-related policies and procedures, email MSK’s Compliance Office at [email protected].