401k, no will, no children, no husband, beneficiary not located, does money just stay in limbo or does it go?

Question

back into deceased persons estate.

Answer 1

A lawyer question, but if there is no beneficiary named or locatable, my guess is back into the estate.  There will be tax consequences.

Answer 2

It goes into the estate and eventually gets absorbed by the state if no one claims  it.

Please, write a simple will, give it to a friend, relative or charity. Designate them on your 401k.