5 C.F.R. § 1655.3
Information concerning the cost of a loan
Information concerning the cost of a loan is provided in the booklet TSP Loan Program (available on the TSP Web site, from the participant's personnel office or service, or from the TSP). From this information, a participant can determine the effects of a loan on his or her final account balance and can compare the cost of a loan to that of other sources of financing.