1600.31—Accounts eligible for transfer.
(a)
A participant who has an open TSP account and is entitled to receive (or receives) an eligible rollover distribution, within the meaning of I.R.C. section 402(c)(4) (26 U.S.C. 402(c)(4) ), from an eligible employer plan or a rollover contribution, within the meaning of I.R.C. section 408(d)(3) (26 U.S.C. 408(d)(3) ), from a traditional IRA may cause to be transferred (or transfer) that distribution into his or her TSP account.
(b)
The only balances that the TSP will accept are balances that would otherwise be includible in gross income if the distribution were paid to the participant. The TSP will not accept any balances that have already been subjected to Federal income tax (after-tax monies) or balances from a uniformed services TSP account that will not be subject to Federal income tax (tax-exempt monies).