John Walker, MD
Vascular & Interventional Radiology · San Antonio, TXNPI 1477780344
Payments from drug & device makers
What this record shows
The money is spread across several categories — consulting fees (48.2%), speaking fees and food and beverage — rather than concentrated in one kind of arrangement. 20 manufacturers reported payments, led by Guerbet LLC at 54.7% of the total.
Across 70 payments — averaging $391.56 each. Meals, travel, consulting and speaking fees, gifts and royalties reported by drug and device makers.
- Guerbet LLC$15K
- Argon Medical Devices, Inc.$4K
- Shionogi Inc$3K
- Boston Scientific$3K
- Sirtex Medical Inc$1K
- Cook Medical LLC$400
- plus $1K from 14 others
Across 2 payments — averaging $1363.50 each. Payments tied to a research study. These frequently flow through the physician to a hospital or research institution rather than to the physician personally.
- Boston Scientific$3K
What the payments were for
- Consulting fees$13,22548%
- Speaking & faculty fees$8,50031%
- Travel & lodging$2,0287%
- Food & beverage$3,64413%
- Entertainment$120%
General payments by program year
Who reported the general payments
Companies are grouped under their corporate parent — a single manufacturer often files under several CMS reporting entities. Research and ownership payments are counted separately and are not in this table.
| Company | Payments | Total |
|---|---|---|
| Guerbet LLC | 4 | $15,000 |
| Argon Medical Devices, Inc. | 1 | $3,500 |
| Shionogi Inc | 3 | $3,244 |
| Boston Scientific | 14 | $2,684 |
| Sirtex Medical Inc | 9 | $1,440 |
| Cook Medical LLC | 5 | $400 |
| Medtronic | 8 | $321 |
| Johnson & Johnson(2 entities) | 7 | $267 |
| Bard Peripheral Vascular, Inc. | 2 | $181 |
| Inari Medical, Inc. | 5 | $163 |
| Penumbra, Inc. | 2 | $44 |
| Cascination AG | 1 | $29 |
| Cardiva Medical, Inc. | 1 | $27 |
| Trisalus Life Sciences, Inc. | 2 | $27 |
| Siemens Medical Solutions USA, Inc. | 1 | $19 |
| Angiodynamics, Inc. | 1 | $16 |
| Baylis Medical Technologies Inc. | 1 | $15 |
| Smiths Medical ASD, Inc. | 1 | $12 |
| EKOS Corporation | 1 | $12 |
| Dova Pharmaceuticals | 1 | $11 |
What the payments were tied to
Products named in the reported payments. Only payments of $100 or more are attributed here — the typical reported payment nationally is a meal worth about $16, and listing those product-by-product would be noise.
- Lipiodol$15,000
- TLAB$3,500
- Mulpleta$3,225
- TheraSphere Y90 Glass Microspheres 10 GBq$2,321
- LAVA LES (Liquid Embolic System)$1,209
- Rosch-Uchida$139
- Cook Medical Embolization$138
- SPYGLASS$130
- THERASPHERE$116
- Certus 140$111
- FLOWTRIEVER CATHETER, S$100
- CT THROMBECTOMY SYSTEM KIT$100
How this compares
$27,409 in reported general payments places this provider in the 85th percentile of 299 vascular & interventional radiology providers in Texas.
See all vascular & interventional radiology providers in Texas →
Medicare billing
What this is not: this is the amount Original Medicare Part B allowed for services this provider billed in 2024. It is not their income. It excludes Medicare Advantage — now more than half of all Medicare enrollment — along with Medicaid and all commercial insurance, and it is gross practice revenue before staff, rent, supplies and malpractice premiums. CMS also suppresses any figure covering ten or fewer patients, so low-volume providers appear smaller than they are.
Most prescribed under Part D
| Drug | Claims | Cost to plans & patients |
|---|---|---|
| Ondansetron OdtOndansetron | 19 | $196 |
| Hydrocodone-AcetaminophenHydrocodone/Acetaminophen | 20 | $123 |
Paid to pharmacies, not to this prescriber.
Other vascular & interventional radiology in San Antonio
- Jorge LoperaSan Antonio$76K
- Matthew Czar TaonSan Antonio$10K
- Orlando DiazHouston$611K
- Rahul ShethHouston$410K
- Miguel MonteroHouston$386K
- Joshua KubanHouston$301K
- Peiman HabibollahiHouston$254K
- Ahmed Abdel AalHouston$147K
- Varshana GurusamyHouston$141K
- Sanjeeva KalvaDallas$128K
Where these figures come from
- Payments: CMS Open Payments, program years 2019–2025 (publication P06302026_06032026).
- Billing: Medicare Physician & Other Practitioners, data year 2024. Original Medicare Part B only.
- Identity: NPPES NPI Registry, July 2026.