I took all the cash value out of my parents life insurance policies to qualify them for Medicaid. Do those policies still exist?

I would think if you cashed them out, then they are essentially closed. So, no IMHO, they are null now.
Did you cash out a whole life policy? I know when mother did that, it was really pennies on the dollar--sadly. And no, once they cashed that out, the policy was no longer worth anything.
You can certainly check with the companies that issued them. If you are not receiving any kind of statement any more that's a pretty good indication they're closed.

No once you cash them out, they are no longer existing. AND you must prove to Medicaid where the money went. They really hate it when an asset just disappears.