Q: I am under the Federal Employees Retirement System with 10 years of frozen Civil Service Retirement System. I withdrew my CSRS and need to redeposit $30,000 to receive full benefits. At retirement, can I take money out of my Thrift Savings Plan to pay this redeposit?
A: You are only permitted to take withdrawals from the TSP under the usual restrictions. There is not special exception for this purpose.
— Mike Miles