The SDN List, short for the Specially Designated Nationals and Blocked Persons List, is a list maintained by the U.S. Treasury’s Office of Foreign Assets Control (OFAC) that identifies individuals, companies, and other entities that U.S. persons are generally prohibited from doing business with.Â
The assets of parties on the list that fall within U.S. jurisdiction are blocked, and dealing with them can expose an organization to serious penalties.
The SDN list is one of the most consequential sanctions lists in the world. It is also one of the easiest to get wrong, because a party can be blocked without ever appearing on the list by name.
Who is on the SDN List?
The SDN List reflects U.S. foreign policy and national security priorities, so who ends up on it follows from those objectives.
It includes individuals, companies, and entities owned or controlled by, or acting on behalf of, targeted countries. It also includes people and groups designated under programs that are not tied to a specific country, such as terrorists and narcotics traffickers. Each entry carries names, common aliases, and other identifying details to help organizations match against it.
Designations usually stem from Executive Orders or statutory authorities such as the International Emergency Economic Powers Act and the Foreign Narcotics Kingpin Designation Act. Once a party is designated, its name is added to the list, which OFAC publishes and updates on its website.
What does being on the SDN List mean?
Landing on the SDN List carries immediate legal weight. It is not a watchlist or an advisory.
The property and interests of a listed party that are within the United States, or in the possession or control of a U.S. person, are blocked, meaning frozen.Â
U.S. persons are broadly prohibited from transacting with that party, and the prohibition reaches financial transfers, goods, services, and even indirect dealings. When property becomes blocked, it also has to be reported to OFAC, generally within 10 business days.
In effect, a listed party is cut off from the U.S. financial system.
The 50 Percent Rule
This is the part that catches organizations by surprise, and the reason name screening alone is not enough.
Under OFAC’s 50 Percent Rule, any entity that is owned 50 percent or more, directly or indirectly and in the aggregate, by one or more blocked persons is itself blocked, even if that entity never appears on the SDN List by name. The rule is based on ownership, not control, and the ownership of multiple blocked persons is added together to reach the threshold.
The practical consequence is significant. An organization can screen a company’s name against the SDN List, find nothing, and still be dealing with a blocked entity because of who owns it. Meeting the rule requires ownership due diligence, not just a name check.
U.S. persons are broadly prohibited from transacting with that party, and the prohibition reaches financial transfers, goods, services, and even indirect dealings.
Who has to comply, and what are the penalties?
OFAC sanctions apply to all U.S. persons, which includes U.S. citizens, permanent residents, anyone within the United States, and U.S.-incorporated entities.
Enforcement operates on a strict liability standard. A violation can occur without any intent or knowledge, so an organization can be penalized even if it had no reasonable way to know a counterparty was blocked.Â
Civil penalties can reach into the hundreds of thousands of dollars per violation, and the most serious cases carry criminal fines and potential imprisonment.Â
OFAC does weigh mitigating factors, such as voluntary self-disclosure and a strong compliance program, when it assesses a violation.
The SDN List vs. healthcare exclusion lists
For healthcare compliance teams, the SDN List is easy to confuse with the exclusion lists they check more often, so the distinction is worth making clear.
The SDN List enforces economic and trade sanctions administered by the Treasury for foreign policy and national security reasons. The OIG exclusion list and the SAM exclusion list, by contrast, bar parties from federal healthcare programs and federal contracts. Different agencies, different authorities, different scope.
A party can appear on one and not the others, which is why a screening program built only around healthcare exclusions can miss a sanctioned party entirely. The SDN List is also just one of several lists OFAC maintains, alongside sources like the Sectoral Sanctions Identifications List, so checking the SDN List alone still leaves gaps.
How the SDN List fits into healthcare screening
Healthcare organizations are U.S. persons and businesses, so OFAC sanctions apply to them the same way they apply to any other company. In practice, that means screening the workforce and vendors against the SDN List as part of a broader sanctions screening program.
Timing is the harder part. The SDN List is updated frequently and on no fixed schedule, sometimes with hundreds of entries added at once.Â
A one-time check at onboarding cannot keep up, which is why the list belongs in continuous monitoring rather than a single pass. For the mechanics of running that check, see OFAC check, and for the hiring angle, the healthcare sanctions background check.
How Streamline Verify supports SDN and sanctions screening
Screening a full population of employees and vendors against a list that can change any day, while also covering healthcare exclusion lists, is more than manual checks can sustain.
Platforms like Streamline Verify screen against OFAC sources including the SDN List, along with the OIG LEIE, the SAM exclusion list, and state Medicaid lists, matching name variations and identifiers so potential matches are not missed. The platform continues ongoing exclusion monitoring over time and records each check in a time-stamped audit trail.
By keeping both sanction and exclusion screening continuous and documented, Streamline Verify helps healthcare organizations stay current with a list that rarely stays still.
Want to see how SDN and sanctions screening fit into your compliance workflow?
