Dismissed disabled veteran's school loan payments

[Chappell]

Have a client who is a disabled vet and his school loan payments were dismissed back to 2014. Both the principal and interest were refunded to them. Question is: they have been writing off the interest on their tax return. How do I handle this? Do I have to amend every return back to 2014?

[Lion]

Cash basis taxpayers report income in the year received.