Dr. Mark Brennan, DO
What this data tells you about Dr. Brennan
Dr. Mark Brennan is a surgery specialist in Johnson City, NY, with 21 years of NPI registration. Based on federal Medicare data, Dr. Brennan performed 174 Medicare services in 2023. These records do not provide a deduplicated patient total.
Between the years covered by Open Payments, Dr. Brennan received a total of $24,436 from 48 pharmaceutical and/or device companies across 352 payment records. A record can group multiple payments. These transfers are publicly reported through CMS Open Payments. Disclosure alone does not establish their effect on care. A reliable breakdown by payment category is not available in this snapshot. Patients may wish to discuss these relationships with their provider.
The Data Coverage level for Dr. Brennan is Very High — reflecting how much public federal data is available about this provider. Patients are encouraged to use this data as one of several factors when choosing a healthcare provider.
Medicare Practice Summary — 2023
Medicare Utilization ↗Top procedures by volume
Ranked by number of services performed for Medicare patients. Avg. submitted charge is what the provider billed; avg. Medicare payment is what CMS paid.
| Procedure | Volume | Avg. paid | Avg. submitted |
|---|---|---|---|
| Ultrasound guidance for blood vessel access Use of ultrasound imaging to help locate and access a blood vessel. This guidance assists healthcare providers in performing procedures such as inserting IV lines or drawing blood. |
43 | $11 | $102 |
| Office visit, established patient (20-29 min) An office visit for an existing patient lasting between 20 and 29 minutes. The visit involves medical evaluation and management of the patient's condition. |
34 | $47 | $103 |
| Hemodialysis circuit intervention with balloon dilation A procedure to insert a needle or tube into a hemodialysis circuit and dilate the dialysis segment using a balloon, with radiological review. |
28 | $172 | $640 |
| New patient office visit (30-44 min) An initial office visit for a new patient lasting between 30 and 44 minutes. This code is used when the total time spent on the date of the encounter falls within this range. |
28 | $56 | $151 |
| Insertion of tunneled central venous catheter for infusion, age 5+ A surgical procedure to place a long-term catheter into a large vein for delivering medications or fluids. The catheter is tunneled under the skin to reduce infection risk and provide stable access for patients aged 5 and older. |
21 | $174 | $955 |
| Fluoroscopic guidance for central vein access device Use of live X-ray imaging to guide the placement or removal of a central vein access device. |
20 | $14 | $49 |
Industry Payment Transparency
Open Payments through 2024 ↗Payment categories are unavailable while the source breakdown is being rebuilt. Company and year totals do not identify how much belongs to each category.
Payment trend by year
Annual totals from pharmaceutical and medical device companies.
Payments by company (2024)
All-time payments by company (2018-2024) ›
Associated products mentioned in payments ›
Geographic Context
3.0 mi
Data Sources
| Provider Registry | ✓ NPPES | NPPES snapshot; verify current record |
| Medicare Enrollment | ✓ PECOS | PECOS snapshot |
| Practice Data | ✓ Medicare Util. | Annual (CY lag) |
| Industry Payments | ✓ Open Payments | CY 2024 |
| Disciplinary History | — Not included | N/A |
This provider has data in 4 of 4 available federal datasets, with a Data Coverage level of Very High. This reflects how much public data is available about a provider. How we calculate this →
Summary
Dr. Brennan is a clinical cardiology specialist, with moderate Medicare volume, with 21 years of NPI registration.
This summary is auto-generated from federal data, describing data availability and patterns. Read our methodology →
Frequently Asked Questions
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This page combines public CMS records with calculated summaries and explanatory procedure labels. These transformations are not verbatim federal records. Sources: NPPES ↗, Open Payments ↗, Medicare Provider Utilization ↗, and PECOS. Publication is mandated by the Physician Payments Sunshine Act (§6002 ACA, 42 U.S.C. §1320a-7h) and the Freedom of Information Act.
This page is not medical advice, an endorsement, a recommendation, or a quality rating. Data Coverage reflects data completeness — how much federal information exists for this provider — not clinical performance, patient outcomes, or quality of care. Always verify information directly with the provider and consult a licensed clinician before making medical decisions.
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