Hi LB,
Try this.
If your Master list starts in A1, and your 2nd list starts in B1:
Place this formula in C1 and fill down to the last row of data in Column A.
=IF(ISERROR(MATCH(A1,$B$1:$B$5,0)),"",INDEX($B$1:$ B$5,MATCH(A1,$B$1:$B$5,0)))
Regards - Dave.