As of 2016, the 1042-S Filer is a module that can be added to the W2/1099 Forms Filer (base software that is required). The 1042-T will be in the 1042-S filer since it is the required transmittal form for the 1042-S.
The 1042-S was originally, and is still part of the 2015 W2/1099 Forms module (which is required) and the 1042-T is in the Forms Filer Plus module. Please call our Sales Department, 800-536-1099 to purchase the product.
Unfortunately, there is no way to transfer the information from the 1042S to the 1042.