tub drain rough in

How far do I have to go with a tub drain rough-in. Is it just up through the trap or do I need to install the tub along with the drain and overflow assy? This will be inspected rough-in and final.

Also, if to the trap is enough, how do I put the tub and the drain + overflow assy in later? I have access from below right now, but will probably not later on. However, I may still have access through the wall from another room to the drain end of the tub later on. This is all glued PVC DWV.

Thanks,

Joel

the tub installation is part of the rough-in. install the whole thing to save any hassle of dealing with a tub once other areas of the build have progressed...