John Leung, MD
Gastroenterology · Boston, MANPI 1447328711
Payments from drug & device makers
Across 1,596 payments — averaging $1767.38 each. Meals, travel, consulting and speaking fees, gifts and royalties reported by drug and device makers.
- Regeneron$671K
- AstraZeneca$586K
- Sanofi$257K
- Regeneron Healthcare Solutions, Inc.$219K
- Takeda Pharmaceuticals U.S.A., Inc.$215K
- Bristol Myers Squibb$147K
- plus $725K from 49 others
Across 14 payments — averaging $842.41 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.
- Regeneron$10K
- AbbVie$2K
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.
How this compares
$2,820,746 in reported general payments places this provider in the 95th percentile of 579 gastroenterology providers in Massachusetts.
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 gastroenterology in Boston
- Ramnik XavierBoston$14.3M
- Scott SnapperBoston$4.9M
- Jessica AllegrettiBoston$3.3M
- Michael DouganBoston$2M
- Raymond ChungBoston$1.4M
- Kathleen CoreyBoston$1.4M
- Joshua KorzenikBoston$1.2M
- Hiroyuki AiharaBoston$988K
- Carlo TraversoBoston$987K
- Gaurav GaihaBoston$881K
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.