Acknowledgment of risk
Primary source
Verbatim text below is from the Electronic Code of Federal Regulations (eCFR), a public-domain U.S. government work. Always verify the current version with the eCFR before relying on it for any legal matter.
Full Text
(a) Uniformed services participants who first entered service prior to January 1, 2018, and who have not elected to be covered by BRS and civilian participants who enrolled prior to September 5, 2015, must execute an acknowledgement of risk in order to invest in a TSP core fund other than the G Fund. If a required acknowledgment of risk has not been executed, no transactions involving the fund(s) for which the acknowledgment is required will be accepted.
(b) The acknowledgment of risk may be executed in association with an investment election, a fund reallocation, or a fund transfer in the form and manner prescribed by the TSP record keeper.
This is legal information, not legal advice. Laws vary by jurisdiction and change frequently. Always verify current law with official sources and consult a licensed attorney in your jurisdiction for advice on your specific situation.