Gailen Marshall, MD
Allergy & Immunology · Jackson, MSNPI 1609810894
Payments from drug & device makers
What this record shows
This record is dominated by consulting fees: $3,300 of the $3,628 with a category attached, or 91.0%. Genentech USA, Inc. accounts for 91.0% of it on its own, with 6 other manufacturers making up the rest. 2022 is the largest year on record at $3,337, more than ten times the $213 reported in 2019. That places this record below the midpoint for allergy & immunology clinicians in MS, where the typical reported total is $10,118.
Across 13 payments — averaging $279.06 each. Meals, travel, consulting and speaking fees, gifts and royalties reported by drug and device makers.
- Genentech USA, Inc.$3K
- AstraZeneca$156
- CSL Behring$58
- GSK$44
- Novartis$35
- Sobi, Inc$18
- plus $17 from 1 others
Across 54 payments — averaging $4890.90 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.
- CSL Behring$136K
- Regeneron$67K
- GSK$58K
- Astrazeneca AB$2K
- Novartis$1K
What the payments were for
- Consulting fees$3,30091%
- Food & beverage$3289%
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 |
|---|---|---|
| Genentech USA, Inc. | 1 | $3,300 |
| AstraZeneca | 3 | $156 |
| CSL Behring | 2 | $58 |
| GSK | 3 | $44 |
| Novartis | 2 | $35 |
| Sobi, Inc | 1 | $18 |
| Johnson & Johnson | 1 | $17 |
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.
How this compares
$3,628 in reported general payments places this provider in the 35th percentile of 28 allergy & immunology providers in Mississippi.
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.
Other allergy & immunology in Jackson
- Todd AdkinsJackson$226K
- Daniel VenarskeJackson$156K
- Dexter WalcottJackson$154K
- Chelle WilhelmJackson$61K
- Joshua PhillipsJackson$20K
- Claire RosenblattJackson$11K
- James HaltomJackson$11K
- Sheryll VincentJackson$3K
- Matthew ElliottJackson$862
- Stephen KempJackson$68
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.