I'm really not a fan of the subject to. Lots of potential issues, and it's really not for me.
Call an attorney, but likely that mortgage will have to get paid off before you can get out from underneath it.
There's probably an acceleration clause on the mortgage, so if the lender knows about the subject to and change on the deed you / the investor might have to pay of the note immediately. Careful on that one.
@Blair Poelman agreed usually bad idea for seller... puts the seller totally at risk for
1. payments not being made and their credit trashed
2. they go to buy something else but can' t becasue this mortgage is still in their name.. ( no one told them that would happen)
3. loan is called buyer can't refi or sell.. and now seller has a NOD on their credit which is about the worse thing that can happen to someone's credit.
4. Seller is no longer in title simply nothing they can do.. buyer puts junior debt behind and then defaults.
just so many things that do not favor seller... and of course you have sharks that do this as a scheme and I won't even go into what they do so not to give any of the bad actors ideas LOL