William O'brien is named as a lobbyist on federal disclosure filings for 1 client through Amgen, Inc.. The most recent filing naming them posted in October 2026. Issues reported include Health Issues, Medicare/Medicaid, Copyright/Patent/Trademark and Taxation/Internal Revenue Code.
Taxation/Internal Revenue Code, Medicare/Medicaid, Health Issues
Activity by year
Year
Clients
Registrants
2026
1
1
2025
1
1
Contributions reported on Form LD-203
Year
Items
Total
2026
2
$3K
Pay is not disclosed for individual lobbyists. Filings do not confirm that records with the same name are one person, so this page may combine people who share the name William O'brien. See the Capitol Clarity rankings and method.