Dr. John B. Marshall, MD
Emergency Medicine (Emergency Medicine Physician)
- Medicare participating
At a glance
- Medical school
- Texas Tech University Health Science Center School of Medicine (2002)
- Years since graduation
- 24
- In the NPI registry since
- 2005
- Medicare patients seen, 2024
- 428
Licensed in Texas since 2004, according to the Texas Medical Board. We show license dates only for the states that publish them in bulk; see which states do. For other states, check the state medical board.
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
- 2002Medical school: Texas Tech University Health Science Center School of Medicine
- 2005Registered 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
-
Emergency Medicine Physician primary
TX license M0164 (first issued 2004; active)
As reported to the NPI registry. To confirm a license is current, check the state medical board.
Where they work
Hospitals
- HCA Florida Memorial Hospital Jacksonville, FL
- HCA Florida Orange PArk Hospital Orange PArk, FL
Medical groups
- Paragon Emergency Services LLC (418 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
- 428
- Services billed
- 709
- Patients’ average age
- 77
| Service | Times | Patients |
|---|---|---|
| Emergency department visit with high level of medical decision making | 73 | 73 |
| Established patient office or other outpatient visit, 20-29 minutes | 52 | 48 |
| Established patient office or other outpatient visit, 30-39 minutes | 37 | 37 |
| New patient office or other outpatient visit, 30-44 minutes | 18 | 18 |
| Emergency department visit with moderate level of medical decision making | 16 | 16 |
| Critical care, first 30-74 minutes | 15 | 14 |
| New patient office or other outpatient visit, 45-59 minutes | 15 | 15 |
| Electrocardiogram (ecg) 1 to 3 leads with review by physician only | 12 | 12 |
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
| Drug | Prescriptions |
|---|---|
| Hydrocodone-Acetaminophen (hydrocodone/acetaminophen) Other prescribers in Dallas, TX | 45 |
| Naproxen Other prescribers in Dallas, TX | 30 |
| Azithromycin Other prescribers in Dallas, TX | 26 |
| Prednisone Other prescribers in Dallas, TX | 25 |
| Methocarbamol Other prescribers in Dallas, TX | 17 |
| Dicyclomine Hcl Other prescribers in Dallas, TX | 16 |
| Metoclopramide Hcl Other prescribers in Dallas, TX | 13 |
| Albuterol Sulfate Hfa (albuterol sulfate) Other prescribers in Dallas, TX | 12 |
| Cephalexin Other prescribers in Dallas, TX | 12 |
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, 1 companies reported 1 payments worth $58.57 in total to this clinician.
| Integra Lifesciences Corporation | $58.57 |
|---|
| Long term medical supply or device loan | $58.57 |
|---|
What the payments were for
| Company | What it was for | Amount |
|---|---|---|
| Integra Lifesciences Corporation Nov 5, 2025 | Long term medical supply or device loan MicroMatrix · Recon-Skin and Wound · in-kind | $58.57 |
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.