Does anyone know how long you are required to keep the loan files for secondary market? (Loans that are originated in-house and sold to Chase, BOA, etc) My brain says 5 years but my heart is just not sure.

Since they hit your books and then were sold, I would think that you would need to retain the files for the same period as you would any other loan that you make that has paid off. That retention would be based on State law, regulation or statute of limitations.