Mark Ewing Chisam, M.D.
Radiation Oncology Physician · Williamsburg, VA
Mark Ewing Chisam, M.D. is a radiation oncology physician with a practice address in Williamsburg, Virginia, and NPI 1053381251, issued on Jan 23, 2006. Check the license (Virginia 0101054200, as entered in NPPES) on the Virginia Department of Health Professions; the Medicare figures below come from public CMS files.
- Name
- Mark Ewing Chisam
- Credential
- M.D.
- Primary taxonomy
- Radiation Oncology Physician 2085R0001X
- License number
- 0101054200 VA
Self-reported in NPPES; status is on the state search - Practice location
- 3901 Treyburn Dr, Williamsburg, VA 23185
- Phone
- (757) 220-4900
- Enumerated
- Jan 23, 2006
- Record last updated
- Oct 3, 2013 (not updated in 13 years: call before relying on the address or phone)
- Fax
- (757) 565-5328
- Medicaid ID
- 1053381251 VA
- Medicare enrollment
- Enrolled (PECOS I20070330000472); accepts Medicare assignment
- Medical or professional school
- Uniformed Services Uhs Fe Hebert School Of Med, 1994
- Entity
- Type 1 · individual
8 nearest radiation oncology physician records → All 137 in Virginia → Look up another NPI →
Also registered at 3901 Treyburn Dr
A shared address usually means a shared clinic or building; it does not show who employs whom.
- Jon Gray, MD, MPHOccupational Medicine Physician1750543146
Verify Mark Ewing Chisam in five checks
- 1IdentityNPI record in CMS NPPESNPI lookupConfirmed in NPPES
- 2LicenseActive license and public ordersVirginia Department of Health Professions
Search for license 0101054200Check the board - 3Other statesLicenses and actions elsewhereDocInfo (FSMB)Not checked
- 4ExclusionsMedicare and Medicaid bansHHS-OIG exclusion listNot checked
- 5CertificationBoard certificationABMS AOA NCCPA AANPNot checked
92% fewer Medicare Part D claims than the average radiation oncology physician in 2024
11 Medicare Part D claims, against an average of 134 among the 4,851 providers of this specialty who prescribed in Part D.
Source: CMS Medicare Part D Prescribers by Provider and Drug, 2024 (data.cms.gov). Part D covers prescriptions for Medicare patients only; drugs with fewer than 11 claims are not published.
The MIPS final score for 2023 (Medicare payment program): 94.1 of 100
The Merit-based Incentive Payment System score is reported for this clinician. Four categories are weighted into the final score; the average among 454,083 clinicians with a measured score was 83.5.
Source: CMS Quality Payment Program, MIPS performance year 2023; category weights for 2023 (qpp.cms.gov).
Industry payments in 2024: $37.21
2 payments; by number, the most common kind was food and beverage; the largest payer was Progenics Pharmaceuticals, Inc. The 3,275 providers of this specialty with any payment received $1,897.85 on average. Payments are reported by manufacturers, not by the provider, and are not a sign of wrongdoing.
Source: CMS Open Payments, program year 2024 (openpaymentsdata.cms.gov); average among providers of this specialty with at least one payment.
Bills Medicare through one group practice
- Riverside Physician Services IncWilliamsburg, VA
Source: CMS Doctors and Clinicians National Downloadable File (the group practices a clinician bills Medicare through) (data.cms.gov).
Mark Ewing Chisam among 137 radiation oncology physician records in Virginia
Mark Ewing Chisam, M.D. is one of 137 radiation oncology physician records with a practice address in Virginia. 81% of them appear in a Medicare file (Part D prescribing, MIPS, Open Payments or Medicare group billing); this one does. Its NPI, issued in 2006, is newer than 14% of them.
- NPI issued2006 · 14% of these records are older, 47% newer
- In a Medicare fileYes · 81% of these records are
- In the CMS Doctors and Clinicians fileYes · 70% of these records are
- Graduated1994 · median 2003 among the 96 with a school on file
- Record last updated2013 · 68% of these records were not updated in five years or more
Source: CMS NPPES, file of Aug 9, 2026, every record with primary taxonomy 2085R0001X and a Virginia practice address; Medicare files: CMS Part D Prescribers 2024, MIPS 2023, Open Payments 2024, Doctors and Clinicians (data.cms.gov).
Radiation Oncology Physician providers in Virginia
There are 137 radiation oncology physician records in Virginia.
All 137 in Virginia → Every provider in Williamsburg → Radiation Oncology Physician nationwide →
The 8 radiation oncology physician records with the nearest ZIP codes
- Marcus BrownRichmond, VA 232201669456570
- Bernard Tisdale, MDRichmond, VA 232201124009600
- Matthew Schutzer, M.D.Richmond, VA 232241629393186
- Abiola Opeitum, MDRichmond, VA 232261447352158
- M Moinuddin Ali, MDRichmond, VA 232351366428419
- Judy Chin, M.D.Richmond, VA 232351427013564
- Christopher Chipko, M.D.Richmond, VA 232351801206818
- Gregory Judy, M.D.Richmond, VA 232351366881807
Common questions
What is Mark Ewing Chisam, M.D.'s NPI number?
Mark Ewing Chisam, M.D.'s National Provider Identifier (NPI) is 1053381251, issued on Jan 23, 2006. An NPI identifies a provider in billing; it is not a license.
Where is Mark Ewing Chisam, M.D. located?
The NPPES record lists a practice address at 3901 Treyburn Dr, Williamsburg, VA, 23185. Phone: (757) 220-4900. Providers update this record themselves, so call before visiting.
How can I verify Mark Ewing Chisam, M.D.'s license?
NPPES lists Virginia license number 0101054200, as entered by the provider. Search the Virginia Department of Health Professions at https://dhp.virginiainteractive.org/lookup/index. The NPPES record confirms identity only; the state search shows license status, expiration and public orders.
How much does Mark Ewing Chisam, M.D. prescribe under Medicare Part D?
In 2024, Mark Ewing Chisam, M.D. had 11 Medicare Part D claims; the average among radiation oncology physician prescribers was 134. Part D covers Medicare prescriptions only.
What is Mark Ewing Chisam, M.D.'s MIPS final score?
The 2023 MIPS final score is 94.1 of 100. The average among 454,083 clinicians with a measured score was 83.5.
Source: CMS National Plan and Provider Enumeration System (NPPES), file of Aug 9, 2026 (NPPES files on CMS.gov); NUCC Health Care Provider Taxonomy. Medicare files from data.cms.gov. An NPI identifies who bills; it is not a license.
Figures on PlainDoctor are read from the federal files each page names (CMS NPPES, Medicare Part D, MIPS, Open Payments; the HHS-OIG exclusion list only as counts) and from Census population estimates, with the file date shown beside them. See our editorial standards & corrections policy, the methodology behind these numbers, or report a data error. Data current as of Aug 9, 2026.