Designating a country as being of "prime money laundering concern" allows the U.S. government to impose one or more of five special measures under Section 311 of the USA PATRIOT Act12. These special measures are intended to protect the U.S. financial system from the risks posed by the designated country, such as money laundering, terrorist financing, or other illicit activities. The fifth special measure, which is the most severe, authorizes the Treasury Department to prohibit U.S. financial institutions from opening or maintaining correspondent or payable-through accounts for foreign financial institutions that involve the designated country12. Correspondent accounts are accounts that enable foreign banks to access the U.S. financial system and provide services to their customers, while payable-through accounts are accounts that allow foreign banks to offer their customers direct access to the U.S. financial system3. Closing these accounts effectively cuts off the designated country from the U.S. financial system and imposes significant costs and burdens on its financial sector.
References:
1: 311 Actions | U.S. Department of the Treasury
2: Press Releases - U.S. Department of the Treasury
3: Anti-Money Laundering Laws and Regulations USA 2023-2024

Explanation/Reference: https://www.fatf-gafi.org/media/fatf/documents/recommendations/Private-Sector-Information- Sharing.pdf (18)

A free-look provision is a period of time, typically 10 to 30 days, in which a new life insurance policy owner can terminate the policy and have their premium refunded1. This can help criminals to launder money by purchasing a policy with illicit funds and then cancelling it within the free-look period to receive a clean check from the insurance company2. This way, they can disguise the source and origin of their funds and avoid any penalties or charges that would otherwise apply to early termination of the policy.
References:
1: Investopedia, What Is a Free Look Period and How Does It Work?
2: FinCEN, Anti-Money Laundering Program and Suspicious Activity Reporting Requirements for Insurance Companies