no. only extremely limited data can be recovered from a PDF. if you are using a windows computer there should be a backup file in the c:\users\users_name\ documents\turbotax folder. it starts with a tilde ~. the old file might be in the recycle bin. Turbotax creates a backup file when you open your tax return. so if you decide not to save it or discard it, the previous version should exist. on the other hand, if it's in the recycle bin, the latest changes might be there.
