What are the OFAC sanctions lists?

OFAC maintains several lists, led by the SDN list, plus sectoral, evader, and financial-institution lists.

TL;DR

TL;DR: The primary OFAC list is the SDN list of Specially Designated Nationals and Blocked Persons; additional lists cover sectoral sanctions, foreign sanctions evaders, and non-SDN entities.

The SDN list

The SDN list is the one most screening tools check first. It holds Specially Designated Nationals and Blocked Persons, currently 19,218 names, and it is the list that triggers a block under OFAC's strict-liability standard. It is maintained by the Office of Foreign Assets Control at the US Treasury.

SSI, FSE, and other lists

Beyond the SDN list, the SSI list covers sectoral sanctions on specific industries, and the FSE list names foreign sanctions evaders. These are narrower in scope but still carry obligations for US persons. The NS-PLC list covers certain non-SDN Palestinian entities, and the CAPTA list addresses foreign financial institutions.

What to screen in practice

For a payment product the practical answer is to screen against the SDN list at minimum, since that is where most enforcement lands. A screening API keeps this simple: it checks the name or wallet and returns ALLOW or BLOCK, and it also tracks the 947 OFAC-listed crypto wallets that a name-only search would miss.

How the lists stay current

These lists change frequently as OFAC adds and removes designations, so screening data must stay fresh. A live screening API syncs the SDN list hourly, which means a designation made this morning blocks a payment this afternoon. A manual PDF search, by contrast, is only as current as the last time someone downloaded it.