MathCad Prime 3.0 to MathCad 15

I am sure that this question has been asked before but I have developed a program in MathCad Prime 3 that I would like to turn over to a programmer who works in MatcCad 15.  The current plan is that he is going to add increased functionality to the program.

I know that MathCad Prime 3 can upload MathCad 15 files but can MathCad Prime 3 files be converted back to MathCad 15 format?