Is the option for multiple (4x per year at least 30 days apart) partial withdrawals available to everyone, or only to age-based (59.5+) withdrawals?
I ask because it would surely make the Roth IRA pipeline method much easier to cut out the step where you have transfer your TSP to a traditional IRA that allows annual rollovers.
It looks like multiple withdrawals are available to EVERYONE provided they are separated from federal service. To make an in-service withdrawal penalty-free, you still need to be 59 1/2 or older (which I know isn't that relevant here).
I'm just pasting this from that link. Looks like 2nd bullet point is the relevant one for ya. Bolding is mine:
Partial Withdrawals
Right now, you’re limited to one partial withdrawal in
your lifetime—either an age-based in-service withdrawal
(when you’re 59½ or older) or a partial post-separation
withdrawal. Under the new policy,
• you’ll be able to take up to four age-based inservice
withdrawals per calendar year1
;
• there will be no limit of the number of partial
withdrawals you can take
after separating from
federal service (except that you won’t be able to
take more than one every 30 days);
• you’ll be able to take partial withdrawals while
you’re receiving post-separation installment
payments; and
• having taken age-based in-service withdrawals
will not prevent you from taking post-separation
partial withdrawals.