Dr. Mark D. Duncan, M.D.
General Surgery (Surgery Physician)
4940 Eastern Ave
Baltimore, MD 21224
Who else practices at this address →
Baltimore city includes primary care (36% of residents) shortage areas. About shortage areas
- Medicare participating
At a glance
- Medical school
- Mayo Medical School (1987)
- Years since graduation
- 39
- In the NPI registry since
- 2006
- Medicare patients seen, 2024
- 116
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
- 1987Medical school: Mayo Medical School
- 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
-
Surgery Physician primary
MD license D51208
As reported to the NPI registry. To confirm a license is current, check the state medical board.
Where they work
Hospitals
- Johns Hopkins Hospital, the Baltimore, MD
- Johns Hopkins Bayview Medical Center Baltimore, MD
Medical groups
- Johns Hopkins University (2,909 clinicians)
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
- 116
- Services billed
- 240
- Patients’ average age
- 73
| Service | Times | Patients |
|---|---|---|
| Established patient office or other outpatient visit, 20-29 minutes | 29 | 26 |
| Established patient office or other outpatient visit, 30-39 minutes | 28 | 22 |
| New patient office or other outpatient visit, 45-59 minutes | 25 | 25 |
| Removal of gallbladder using an endoscope | 19 | 19 |
| Established patient office or other outpatient visit, 40-54 minutes | 18 | 17 |
| New patient office or other outpatient visit, 30-44 minutes | 15 | 15 |
| New patient office or other outpatient visit, 60-74 minutes | 13 | 13 |
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.
Payments from drug and device companies
In 2025, 2 companies reported 2 payments worth $62.72 in total to this clinician.
| Medtronic, Inc. | $55.22 |
|---|---|
| Intuitive Surgical, Inc. | $7.50 |
| Food and Beverage | $62.72 |
|---|
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.