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Dr. Mark Knapp, MD

Hematology & Oncology (Hematology & Oncology Physician)

  • Medicare participating

At a glance

Years since graduation
29
In the NPI registry since
2006
Medicare patients seen, 2024
412

The NPI date is when this clinician registered for a National Provider Identifier, the billing number used on health claims. It is not a license, graduation or board-certification date. NPIs were first issued in May 2005 and became required on claims in 2007–2008, so an early date usually means the clinician was already in practice before then. What an NPI is

Education and training

  • 1997Medical school: University of Cincinnati College of Medicine
  • 2006Registered with an NPI (national billing number; not a license date) — NPIs began in 2005, so practice likely started earlier

Undergraduate school, residency, fellowship, licensing exams and board certification aren’t in public federal data. Board certification can be confirmed with the certifying board (ABMS member boards for MDs, AOA boards for DOs).

Specialties and state licenses

  • Hematology & Oncology Physician primary
    OH license 35078040
  • Medical Oncology Physician
    OH license 35078040

As reported to the NPI registry. To confirm a license is current, check the state medical board.

Map: Hematology & Oncology per capita by county →

Where they work

Hospitals

Medical groups

Hospitals this clinician lists with Medicare, and groups they bill Medicare through (Care Compare). Affiliation doesn’t mean they see patients at every location.

Medicare patients and services

Medicare patients, 2024
412
Services billed
59,176
Patients’ average age
75
Most frequent Medicare services, 2023
ServiceTimesPatients
Injection, epoetin alfa, (for non-esrd use), 1000 units9,62016
Low osmolar contrast material, 300-399 mg/ml iodine concentration, per ml3,90229
Injection, ferric derisomaltose, 10 mg2,50020
Complete blood cell count (red cells, white blood cell, platelets), automated test and automated differential white blood cell count959288
Injection, dexamethasone sodium phosphate, 1 mg62014
Established patient office or other outpatient visit, 20-29 minutes489313
Established patient office or other outpatient visit, 30-39 minutes358171
Injection of drug or substance under skin or into muscle30432
Insertion of needle into vein for collection of blood sample239135
Administration of chemotherapy into vein, 1 hour or less21324

Medicare fee-for-service only. CMS leaves out services billed for fewer than 11 patients. These figures describe a practice’s Medicare work; they aren’t a measure of quality.

Medicare prescriptions

Prescriptions filled under Medicare Part D, including refills. CMS leaves out drugs prescribed fewer than 11 times.

Payments from drug and device companies

In 2025, 17 companies reported 39 payments worth $8,370 in total to this clinician.

By company
Gilead Sciences, Inc.$5,796
Caris Mpi, Inc.$1,044
Avyxa Pharma, LLC$1,000
Aveo Pharmaceuticals, Inc.$78.34
Eisai Inc.$77.68
E.r. Squibb & Sons, L.l.c.$70.28
Pfizer Inc.$67.87
AbbVie Inc.$52.77
By type
Consulting Fee$5,370
Food and Beverage$1,030
Compensation for services other than consulting (speaking, faculty)$1,000
Travel and Lodging$970

What the payments were for

Largest payments other than meals
DateCompanyWhat it was forAmount
Nov 26, 2025Gilead Sciences, Inc.
Nov 26, 2025
Consulting Fee
Trodelvy · ONC
Company’s description;4253500;VEM US;10434264
$4,470
Dec 18, 2025Avyxa Pharma, LLC
Dec 18, 2025
Compensation for services other than consulting (speaking, faculty)$1,000
Aug 7, 2025Caris Mpi, Inc.
Aug 7, 2025
Consulting Fee
MI CANCER SEEK · ONCOLOGY
$900
Nov 14, 2025Gilead Sciences, Inc.
Nov 14, 2025
Travel and Lodging
Trodelvy · ONC · travel to Chicago, IL · in-kind
Company’s description;4253566;VEM US;10434264
$356
Nov 14, 2025Gilead Sciences, Inc.
Nov 14, 2025
Travel and Lodging
Trodelvy · ONC · travel to Chicago, IL · in-kind
Company’s description;4253530;VEM US;10434264
$351
Nov 14, 2025Gilead Sciences, Inc.
Nov 14, 2025
Travel and Lodging
Trodelvy · ONC · travel to Chicago, IL · in-kind
Company’s description;4253457;VEM US;10434264
$220
Nov 14, 2025Gilead Sciences, Inc.
Nov 14, 2025
Travel and Lodging
Trodelvy · ONC · travel to Chicago, IL
Company’s description;4253578;VEM US;10434264
$43.00

Each payment as the company reported it, with the products it named. Meals are counted in the totals above but not listed one by one.

From CMS Open Payments. A payment is not evidence of wrongdoing; many are for consulting, teaching or meals. Clinicians can review and dispute their records with CMS.

Who received the most in Ohio →

Industry-funded research

Named as a principal investigator on 3 industry-funded studies in 2025, from 3 companies. The companies reported $6,428 in research payments for these studies, mostly to the institutions running them.

From CMS Open Payments research payments, where companies name up to five principal investigators per payment. Research payments usually go to hospitals, universities and research sites, not to the investigator personally. A payment is not evidence of wrongdoing.

Other Hematology & Oncology clinicians in Columbus

Sources

NPI registry (CMS NPPES, November 2026; record last updated January 11, 2023), Medicare Care Compare, Medicare Physician & Other Practitioners (2024), Medicare Part D Prescribers (2024) and Open Payments (2025). Information is self-reported or billed data and may be out of date; call before visiting.

NPI 1952359549. Official NPI registry record (opens in a new tab). Clinicians can correct their information in NPPES; changes appear here after our next monthly update.