Can I transfer or roll over money from an existing retirement plan to the TSP?
Yes. Whether you are an active or separated Federal employee you can transfer or roll over money from a
traditional IRA or an eligible employer plan into your
existing TSP account. If you are separated from service, you can transfer money into your TSP account unless you have already made a full withdrawal of your account or are receiving monthly payments.
The TSP can accept funds that were distributed from a traditional IRA or an eligible employer plan (or its designated financial institution). The money that you are transferring or rolling over must be considered an "eligible distribution" under the Internal Revenue Code. If you are considering a transfer, you should check with the administrator of the plan from which you wish to transfer the money (or your tax advisor) to ensure that the funds are eligible for transfer or rollover.
Note: The TSP can only accept transfers that consist of
before-tax money. The money will be subject to income tax when it is eventually paid to you from your TSP account.