Long Huynh-Duc, DO
Rheumatology · Greenville, SCNPI 1447572169
Payments from drug & device makers
What this record shows
This record is dominated by speaking fees: $215,066 of the $278,034 with a category attached, or 77.4%. 43 manufacturers reported payments, led by Lilly USA, LLC at 29.3% of the total. Reporting peaked in 2019 at $143,538 and has fallen 97.3% since, to $3,892 in 2025. Among rheumatology clinicians in SC with any reported payments, this total sits in the top 10% — high for the specialty, which is a reason to read the composition above rather than the number alone.
Across 1,739 payments — averaging $159.88 each. Meals, travel, consulting and speaking fees, gifts and royalties reported by drug and device makers.
- Lilly USA, LLC$81K
- Amgen$75K
- Bristol Myers Squibb$45K
- Mallinckrodt Enterprises LLC$17K
- AstraZeneca$13K
- Regeneron Healthcare Solutions, Inc.$12K
- plus $34K from 37 others
Across 79 payments — averaging $2497.08 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.
- GSK$136K
- Amgen$17K
- E.r. Squibb & Sons, L.L.C.$17K
- Genentech, Inc.$11K
- Janssen Research & Development, LLC$9K
- AbbVie$7K
What the payments were for
- Consulting fees$14,7235%
- Speaking & faculty fees$215,06677%
- Travel & lodging$16,4706%
- Food & beverage$31,40311%
- Education$3720%
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.
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
$278,034 in reported general payments places this provider in the 90th percentile of 123 rheumatology providers in South Carolina.
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 |
|---|---|---|
| Humira(Cf) PenAdalimumab | 102 | $1,136,189 |
| CortrophinCorticotropin | 14 | $944,584 |
| Enbrel SureclickEtanercept | 72 | $639,742 |
| Orencia ClickjectAbatacept | 68 | $438,411 |
| RinvoqUpadacitinib | 50 | $342,092 |
| BenlystaBelimumab | 44 | $241,820 |
| OtezlaApremilast | 30 | $148,167 |
| Cyltezo(Cf) PenAdalimumab-Adbm | 15 | $95,412 |
| KevzaraSarilumab | 20 | $88,243 |
| Hydroxychloroquine Sulfate | 717 | $35,420 |
| Actemra ActpenTocilizumab | 12 | $28,741 |
| MethotrexateMethotrexate Sodium | 512 | $19,033 |
| Diclofenac Sodium | 173 | $10,661 |
| RasuvoMethotrexate/Pf | 11 | $8,263 |
| Leflunomide | 146 | $7,163 |
Paid to pharmacies, not to this prescriber.
Companies that both paid and supply prescribed drugs
These companies both reported payments to this provider and make drugs the provider prescribed under Medicare Part D in 2024. For most specialties this overlap is expected — a cardiologist who is paid by a cardiology drugmaker also treats heart disease. It is shown so the reader can see it, not because it implies anything on its own.
| Company | Paid to this provider | Part D cost of their drugs |
|---|---|---|
| AbbVieRinvoq | $2,449 | $342,09250 claims |
| GSKBenlysta | $1,584 | $241,82044 claims |
| AmgenOtezla | $75,035 | $148,16730 claims |
| SanofiKevzara | $1,649 | $88,24320 claims |
| Medexus Pharma, Inc.Rasuvo | $11 | $8,26311 claims |
| Scilex Pharmaceuticals Inc.Colchicine | $37 | $1,96915 claims |
Reading this fairly. The Part D column is what drug plans and patients paid pharmacies — this provider received none of it, and it reflects how many patients they treat and what those drugs cost. Against peers, this provider's reported payments sit in the 90th percentile of 123 rheumatology providers in South Carolina.
Other rheumatology in Greenville
- Alan BrownGreenville$947K
- Corey EphrussiGreenville$54K
- Suhail KumarGreenville$23K
- Richard KimGreenville$20K
- Gulzar MerchantGreenville$18K
- Jeffrey LawsonGreenville$15K
- Ezinma EzealahGreenville$12K
- Stephen MullisGreenville$8K
- Corwin McGeeGreenville$5K
- Muthamma MachimadaGreenville$5K
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.