What happens to your real identity when you enter a Witness Protection Program?

Assuming that you are given the option to return to your normal life
once all of the craziness blows over assuming that it will,
what happens to your identity in the meantime?

Do you still exist on paper, but in some kind of limbo state?
Do you continue to accrue debt on loans, mortgages, etc?

If someone or a group of someones is out to kill you,
I’m sure you could care less about all of this.
But I am a bit curious how it all works.