5 CFR 1655.16: Reamortization.

(a) When a participant's pay cycle changes for any reason, he or she must notify the TSP record keeper of the change in the form and manner prescribed by the TSP record keeper. Upon notification, the participant's loan will be reamortized to adjust the scheduled payment to an equivalent amount in the new pay cycle. If the new pay cycle results in fewer payments per year and the participant does not reamortize the loan, the loan may be declared a deemed distribution pursuant to § 1655.15(a)(1).

(b) Upon reamortization, the new principal balance of the loan will equal the outstanding principal on the date of reamortization, plus any accrued interest.

(c) The interest rate on a reamortized loan will be the same as the interest rate on the original loan.