
Steven M. Horwitz, MD
Medical Oncologist
Titles
Attending Physician
Clinical Expertise
T Cell Lymphomas; Cutaneous (Skin) Lymphomas; Other non-Hodgkin and Hodgkin Lymphomas
We post reviews for MSK healthcare providers who have at least 30 patient experience surveys completed. If you do not see reviews for a provider, it may be because they do not yet have enough survey responses, or the provider may not be part of the group of healthcare providers included in the survey.
Only outpatient providers are included in the survey. Healthcare providers who only work in the hospital or in urgent care are not included in the survey. Pathologists or researchers who do not provide direct care to patients do not have reviews.
New Patient Appointments
Scheduling a visit is easy. Click below or call us to get started.
Dr. Horwitz accepts the following list of insurance providers. Select your insurance provider to see more details.
Payor Type: Commercial
In Network Coverage Type(s): HMO, EPO PPO, POS, Transplant
Payor Type: Medicare/Medicare Advantage
In Network Coverage Type(s): PPO
Payor Type: Commercial
In Network Coverage Type(s): HMO, PPO
Payor Type: Commercial
In Network Coverage Type(s): PPO, POS, EPO, HMO
Payor Type: Commercial
In Network Coverage Type(s): HMO, EPO PPO, POS
Payor Type: Medicaid/Managed Medicaid
In Network Coverage Type(s): HMO
Payor Type: Commercial
In Network Coverage Type(s): Supplemental
Payor Type: Commercial
In Network Coverage Type(s): PPO, POS, HMO
Payor Type: Commercial
In Network Coverage Type(s): POS, EPO, HMO
Payor Type: Commercial
In Network Coverage Type(s): PPO, POS, EPO, HMO
Payor Type: Medicaid/Managed Medicaid
In Network Coverage Type(s): HMO
Payor Type: Medicare/Medicare Advantage
In Network Coverage Type(s): PPO, HMO
Payor Type: Medicare/Medicare Advantage
In Network Coverage Type(s): PPO, HMO, DSN
Payor Type: Medicaid/Managed Medicaid
In Network Coverage Type(s): HMO
Payor Type: Commercial
In Network Coverage Type(s): PPO
Payor Type: Commercial
In Network Coverage Type(s): HMO, EPO
Payor Type: Medicaid/Managed Medicaid
In Network Coverage Type(s): HMO
Payor Type: Medicare/Medicare Advantage
In Network Coverage Type(s): HMO
Payor Type: Medicare/Medicare Advantage
In Network Coverage Type(s): PPO
Payor Type: Commercial
In Network Coverage Type(s): EPO, HMO, PPO, POS
Payor Type: Medicaid/Managed Medicaid
In Network Coverage Type(s): HMO
Payor Type: Medicare/Medicare Advantage
In Network Coverage Type(s): HMO, PPO
Payor Type: Commercial
In Network Coverage Type(s): PPO EPO
Payor Type: Commercial
In Network Coverage Type(s): HMO
Payor Type: Commercial
In Network Coverage Type(s): PPO
Payor Type: Commercial
In Network Coverage Type(s): EPO
Payor Type: Commercial
In Network Coverage Type(s): EPO
Payor Type: Medicare/Medicare Advantage
In Network Coverage Type(s): PPO, HMO
Payor Type: Medicaid/Managed Medicaid
In Network Coverage Type(s): State Government
Payor Type: Commercial
In Network Coverage Type(s): PPO, POS, EPO
Payor Type: Medicaid/Managed Medicaid
In Network Coverage Type(s): State Government
Payor Type: Medicaid/Managed Medicaid
In Network Coverage Type(s): State Government
Payor Type: Medicare/Medicare Advantage
In Network Coverage Type(s): Federal Government
Payor Type: Commercial
In Network Coverage Type(s): Supplemental
Payor Type: Commercial
In Network Coverage Type(s): PPO/OAP
Payor Type: Other
In Network Coverage Type(s): PPO, POS, EPO, HMO
Payor Type: Medicare/Medicare Advantage
In Network Coverage Type(s): TBD
Payor Type: Commercial
In Network Coverage Type(s): HMO/EPO
Payor Type: Commercial
In Network Coverage Type(s): PPO, EPO
Payor Type: Commercial
In Network Coverage Type(s): State Government
Payor Type: Commercial
In Network Coverage Type(s): PPO, POS, HMO
Payor Type: Commercial
In Network Coverage Type(s): PPO, HMO
Payor Type: Commercial
In Network Coverage Type(s): PPO, POS
Payor Type: Commercial
In Network Coverage Type(s): PPO, POS, HMO
Contact and Location
- 646-608-3725 Office Phone
- Speaks English

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, Case Western Reserve University
Residencies
Internal Medicine - University of Rochester/Strong Memorial Hospital
Fellowships
Medicine - Stanford University Medical Center
Board Certifications
Internal Medicine; Medical Oncology
I am a medical oncologist who focuses on the care of patients with lymphoma, and I have clinical expertise in all types of lymphomas. My research is aimed at developing an improved understanding of new therapies for patients with several less-common types of lymphoma, including T cell lymphomas, cutaneous (skin) lymphomas, Hodgkin disease, and lymphomas in immunosuppressed patients after organ transplant (post-transplant lymphoproliferative disorders or PTLD).
Awards and Honors
- Castle Connolly: America's Top Doctors (2023)
- Castle Connolly: New York Magazine Top Doctors (2013-2021)
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.
Clinical Trials
- Clinical Trials Investigated by Dr. Horwitz
- A Phase I Study Assessing the Addition of Lenalidomide to the Usual Combination Chemotherapy for HTLV-Associated Adult T-Cell Leukemia-Lymphoma
- A Phase I Study of CTX130 Immunotherapy in People with Persistent or Recurrent T-Cell or B-Cell Cancers
- A Phase I/II Study of CFT7455 in People with Non-Hodgkin Lymphoma or Multiple Myeloma
- A Phase IB/II Study of Hu5F9-G4 (Magrolimab) in Combination with Mogamulizumab to Treat Recurrent or Persistent T-Cell Lymphoma
Read more
- A Phase II Study of Brentuximab Vedotin and CHP Chemotherapy in People with Previously Untreated Peripheral T-Cell Lymphoma
- A Phase II Study of Valemetostat Tosylate in People with Persistent Peripheral T-Cell Lymphoma or Adult T-Cell Leukemia/Lymphoma
- Clinical Trials Co-Investigated by Dr. Horwitz
- A Phase 1/2 Study of MT-101 in People with T-Cell Lymphoma
- A Phase I Study of KT-333 in People with Lymphoma and Large Granular Lymphocytic Leukemia
- A Phase I Study of ONO-4685 Immunotherapy in People with T-Cell Lymphoma
- A Phase I Study of Ruxolitinib and Duvelisib to Treat Recurrent or Persistent T-Cell or NK-Cell Lymphomas
- A Phase I Study of SEA-TGT Immunotherapy in People with Classical Hodgkin Lymphoma
- A Phase IB Study of Lacutamab in People with Peripheral T-Cell Lymphoma That Has Come Back
- A Phase II Study Assessing the Addition of Duvelisib or CC-486 to the Usual Treatment for Peripheral T-Cell Lymphoma
- A Phase II Study of Pembrolizumab Immunotherapy plus Gemcitabine to Treat Advanced Mycosis Fungoides or Sézary Syndrome
- A Phase II Study of Ruxolitinib in Patients with Persistent or Recurrent T-Cell or NK-Cell Lymphoma
- A Phase II Study to Determine the Optimal Dose of Brentuximab Vedotin for Mycosis Fungoides and Lymphomatoid Papulosis
- A Pilot Study of Pembrolizumab Immunotherapy in Patients with Extranodal NK/T-cell Nasal-Type Lymphoma

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. Horwitz’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 PubMedPatient Reviews
At MSK, we’re committed to delivering the best care to every patient. We use feedback from our patients to continue to improve our care. We also post patient reviews online to help you make healthcare choices. Learn more about our patient experience reviews.
Disclosures
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.
Steven M. Horwitz discloses the following relationships and financial interests:
-
Affimed
Provision of Services -
Canadian Hematology Society
Provision of Services -
Cimeio Therapeutics AG
Provision of Services -
Clinical Education Alliance, LLC
Provision of Services -
Curio Science LLC
Provision of Services -
Cutaneous Lymphoma Foundation
Fiduciary Role/Position -
DKMS
Fiduciary Role/Position -
Daiichi Sankyo
Provision of Services -
Health Advances LLC
Provision of Services -
International Society for Cutaneous Lymphomas
Fiduciary Role/Position -
Israel Biotech Fund
Provision of Services -
Japanese Society of Medical Oncology
Provision of Services -
Kyowa Hakko Kirin Pharma
Provision of Services -
Medscape
Provision of Services
-
National Comprehensive Cancer Network
Fiduciary Role/Position -
Ology Medical Education
Provision of Services -
Ono Pharma
Provision of Services -
Physicians' Education Resource
Provision of Services -
Saudi Oncology Society
Provision of Services -
Secura Bio, Inc.
Provision of Services -
Shoreline Biosciences, Inc.
Provision of Services -
Simposio Internacional de Onco-Hematologia (SINTOMA)
Provision of Services -
Takeda Millennium
Provision of Services -
Triangle Insights Group, LLC
Provision of Services -
Tubulis GmbH
Provision of Services -
Verrill Dana LLP
Provision of Services -
i3 Health
Provision of Services
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, 2021 through disclosure submission in spring 2022). 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].