Right, I'm starting a new thread because some people are seriously confusing the issue in the comments and I don't feel like getting downvoted into oblivion for not addressing the specific scenario that they're concerned with that you didn't ask about. I'll delete my other responses and try to be specific and clear here, including a disclaimer about the scenario they're mixing this up with.

If you wish to transfer your loans to FedLoan, FedLoan will do that for you when you first submit your PSLF certification. Recommend doing that early just so you know what you're working with - no need to wait until you have a full year of qualifying employment. I did mine within my first month at my job. They will do it for any loans that qualify (you will provide them with a list). This IS loan consolidation, but FedLoan keeps each segment separate and tallies each payment separately. This means you can have differing forgiveness dates for each loan segment (depending on prior payments and when they were added to FedLoan in relation to the others). You will need to provide a list of the loans to consolidate.

If, however, you wish to consolidate non-qualifying loans into a qualifying loan, you may need to manually do that (I'm not sure whether FedLoan will do that as part of PSLF, though I can tell you they did pull in my personal private loans that qualified) and I cannot advise, other than to say: only payments made toward qualifying loans will qualify for PSLF, so ensure your loans qualify for PSLF before you pay toward them with this expectation.

Any loans that FedLoan has consolidated in any way will not be sent back to the former providers if you leave public service. FedLoan is your new provider, because your loans have been consolidated under them.