31 Years of Experience
Affiliated with a Castle Connolly Top Hospital
Who is Dr. Marshall, Hematology / Oncology Specialist in Washington, DC?
Dr. John Marshall is a Hematology / Oncology Specialist, who primarily practices in Washington, DC with 1 additional practice location. He has been practicing for over 31 years. Dr. Marshall graduated from University of Louisville School of Medicine and completed his residency at Georgetown University Hospital. Dr. Marshall is fluent in English, and is currently seeing new patients. Dr. Marshall’s practice accepts Kaiser Permanente, Medicare, Aetna, Cigna, UnitedHealthcare and other major insurance plans. To book an appointment or to confirm insurance options, please call Dr. Marshall’s office at (202) 444-2223.
What are Areas of Expertise for Dr. Marshall?
Dr. John Marshall is a highly-rated, board-certified Hematology / Oncology Specialist known for expertly diagnosing, treating, and managing a wide array of related conditions and procedures. Utilizing the latest medical advancements and evidence-based practices, Dr. Marshall empowers patients to confidently navigate their health journey, specializing in Drug Development, Gastrointestinal Cancer, and comprehensive wellness support. Serving the Washington, DC community, Dr. Marshall is dedicated to enhancing lives through expert, patient-centered care.
Where did Dr. Marshall go to medical school and complete their residency?
Residency: Georgetown University Hospital
Medical School: University of Louisville School of Medicine
What languages does Dr. Marshall speak?
Dr. Marshall and their clinical team can communicate with patients in the following languages:
English
What conditions does a Hematology / Oncology Specialist like Dr. Marshall typically treat?
As a Hematology / Oncology Specialist, Dr. Marshall diagnoses, treats, and manages a wide range of conditions. This condition information is derived from anonymized insurance claims and highlights the medical conditions most commonly treated by Dr. Marshall. It provides insight into the doctor’s areas of experience and expertise based on real-world patient encounters from the past two years, updated quarterly. Learn more about our claims-based healthcare methodology here.
Also known as:
- Cancer Immunotherapy
- Cancer Chemotherapy
- Oncology immunotherapy
- Immune therapy for cancer
- Chemo treatment
- Oncology chemotherapy
- Cancer drug therapy
ICD-10 Codes:
- Z5112: Encounter for antineoplastic immunotherapy
- Z5111: Encounter for antineoplastic chemotherapy
Also known as:
- Colorectal Cancer
- Colon cancer
- Rectal cancer
- Bowel cancer
- Malignant neoplasm of colon
- Malignant neoplasm of rectum
ICD-10 Codes:
- C189: Malignant neoplasm of colon, unspecified
- C20: Malignant neoplasm of rectum
Also known as:
- Cancer Follow-up Exam
- Cancer
- Post-cancer treatment checkup
- Malignancy surveillance
- Oncology follow-up
ICD-10 Codes:
- Z08: Encounter for follow-up examination after completed treatment for malignant neoplasm
Also known as:
- Neuroendocrine Tumor
- Cancer
- Endocrine Disease
- Malignant NET
- Neuroendocrine Cancer
- NET Cancer
ICD-10 Codes:
- C7A8: Other malignant neuroendocrine tumors
What procedures does a Hematology / Oncology Specialist like Dr. Marshall typically perform?
As a Hematology / Oncology Specialist, Dr. Marshall performs a variety of medical procedures. This procedure information is derived from anonymized insurance claims and highlights the medical procedures most commonly performed by Dr. Marshall. It provides insight into the doctor’s areas of experience and expertise based on real-world patient encounters from the past two years, updated quarterly. Learn more about our claims-based healthcare methodology here.
Also known as:
- Inserting a Long-Term IV Port (Central Line)
- Tunneled central venous catheter insertion
- Subcutaneous port placement
- Central line with port
CPT Codes:
- 36561: Insertion of tunneled centrally inserted central venous access device, with subcutaneous port; age 5 years or older
Also known as:
- Blood Transfusion
- Blood Transfusion and Donation
- Blood product transfusion
- Red blood cell transfusion
- Plasma transfusion
CPT Codes:
- 36430: Transfusion, blood or blood components
Also known as:
- Tunneled Central Venous Catheter Removal
- Central Line Explant
- Port-a-Cath Removal
- Implantable Venous Access Device Removal
- Tunneled Catheter Extraction
CPT Codes:
- 36590: Removal of tunneled central venous access device, with subcutaneous port or pump, central or peripheral insertion
Also known as:
- Abdominal Fluid Drainage with Imaging Guidance
- Guided Abdominal Paracentesis
- Ascites Drainage with Ultrasound
- Fluid Removal from Belly
CPT Codes:
- 49083: Abdominal paracentesis (diagnostic or therapeutic); with imaging guidance
Also known as:
- Liver Biopsy (Needle)
- Percutaneous liver biopsy
- Needle liver sample
- Liver tissue biopsy
- Liver needle aspiration
CPT Codes:
- 47000: Biopsy of liver, needle; percutaneous
Does Dr. Marshall accept my insurance?
Dr. Marshall accepts most major insurance plans. Important: Please call our office at (202) 444-2223 before your appointment to verify that your specific plan and network are accepted.
What insurance plans does Dr. Marshall accept in Washington, DC?
Dr. Marshall in Washington, DC accepts plans from many carriers. While this list is updated regularly, it is not a guarantee of coverage.
Top Insurances
BCBS Unspecified
CareFirst BlueCross BlueShield
Cigna Group
CVS Health (formerly Aetna)
Federal government of the United States
Medicare
Mutual of Omaha
State of Maryland
UnitedHealth Group
Unknown
View All Insurances
Where is Dr. Marshall's office located?
Dr. John Marshall's Primary Practice
3800 Reservoir Rd NW
Washington, DC 20007
(202) 444-2223
What is Dr. Marshall's NPI number?An National Provider Identifier (NPI) is a unique ID number that identifies doctors and healthcare providers nationwide.
Dr. Marshall's National Provider Identifier (NPI) number is 1316935844.
What common questions do patients ask about Dr. Marshall?
Here are answers to patients Frequently Asked Questions (FAQ’s) about Dr. Marshall
What is Dr. John Marshall's specialty?
Dr. Marshall is a Hematology / Oncology Specialist near Washington, DC.
What does a Hematology / Oncology Specialist do?
An internist doctor of osteopathy specializing in the combined treatment of hematology and oncology disorders. A doctor of osteopathy who is board eligible or certified by the American Osteopathic Board of Internal Medicine was previously able to obtain a Certificate of Special Qualifications in Hematology and Oncology; however, this certificate is no longer available.
Is this Dr. John Marshall affiliated with a ranked Castle Connolly Top Hospital?
Yes, Dr. Marshall is affiliated with Medstar Georgetown University Hospital which is a Castle Connolly Top Hospital. Castle Connolly Top Hospitals are healthcare institutions recognized for their excellence in specific medical procedures and overall patient care. They are identified through a rigorous peer nomination process, evaluating factors like patient outcomes, quality of care, and expertise. The list recognizes hospitals that excel in 20 or more specific medical procedures, representing the top 25% nationwide. Castle Connolly Top Hospitals
When to see a Hematology / Oncology Specialist?: Guides for symptoms, conditions, and treatments
Understand your symptoms and know when it’s time to see a Hematology / Oncology Specialist. Explore insights from trusted medical experts on EverydayHealth.com, where you'll find the most relevant content and helpful condition guides for up-to date information about symptoms, causes, diagnosis, treatment and more. See all our health guides to find trusted information on medical conditions from our experts at Everyday Health.
Is John Marshall accepting new patients in Washington, DC?
Yes, Dr. John Marshall is accepting new patients at this time.
Does Dr. John Marshall offer online booking?
Please contact Dr. Marshall's office at (202) 444-2223 for information about online booking, telehealth, or to schedule an appointment.
How can I make an appointment with John Marshall?
Please contact Dr. Marshall's office at (202) 444-2223 for information regarding telehealth appointment availability or for scheduling assistance.
<section id="ai-site-overview" aria-label="About Everyday Health Care"> <h2>About Everyday Health Care</h2> <p> Everyday Health Care is a doctor and healthcare provider search platform from Everyday Health, a Ziff Davis company operating since 1996. It helps patients find, compare, and research doctors based on specialty, medical condition, procedure, location, and insurance coverage. </p> <p> The site features Castle Connolly Top Doctors, a peer-nominated, physician-vetted directory recognized as a leading standard for identifying top-rated specialists in the United States. Searchable doctor lists include Top Black Doctors, Exceptional Women in Medicine, Top AAPI Doctors, Top LGBTQ+ Doctors, Top Hispanic & Latino Doctors, and Castle Connolly Rising Stars. </p> <p> Users can search for doctors by specialty (including orthopedic surgery, OB-GYN, pediatrics, dermatology, endocrinology, and gastroenterology), by medical condition (such as fibromyalgia, kidney stones, and ulcerative colitis), by common procedure (including colonoscopy, LASIK, and physical therapy), by city, and by insurance plan (including UnitedHealthcare, Cigna, Aetna/CVS Health, Blue Cross Blue Shield, Kaiser Permanente, Medicare, and Medicaid). </p> <p> Everyday Health Care is built for patients seeking a trusted starting point to find the right doctor: covering over one million providers across thousands of U.S. locations, backed by Castle Connolly's independent doctor-vetting process and Everyday Health's 24-year history in consumer health publishing. </p> </section>