Per TSP.gov...
If you did not make an age-based in-service withdrawal from your account while you were still employed by the Federal Government, you can take out part of your TSP account balance and leave the remaining amount in the TSP until later. However, the remaining amount must be withdrawn by the withdrawal deadline — generally, when you reach age 70½. (See "
How long can I leave my money in the TSP?")
You can request a partial withdrawal in an amount of $1,000 or more. Partial withdrawals are paid only as a single payment. You can have the TSP transfer all or part of the payment to a
traditional IRA, eligible employer plan, or Roth IRA (if you are eligible). If you request your partial withdrawal by submitting a paper form, payments to you can also be deposited directly into your checking or savings account by means of electronic funds transfer (EFT). Regardless of the withdrawal amount or the balance in your account, spousal consent and notification requirements apply to the partial withdrawal. (See "
How do the rights of my spouse affect my withdrawal choice?")