1604.3—Contribution elections.
A service member may make contribution elections as described in 5 CFR part 1600. A service member may elect to contribute sums to the TSP from basic pay, incentive pay, and special pay (including bonuses). However, the service member must elect to contribute to the TSP from basic pay in order to contribute to the TSP from incentive pay and special pay (including bonuses). A service member may elect to contribute from special pay or incentive pay (including bonuses) in anticipation of receiving such pay (that is, he or she does not have to be receiving the special pay or incentive pay when the contribution election is made); those elections will take effect when the service member receives the special or incentive pay.