For a rental property, non-deductible amounts that you can carry forward to the next tax year are indicated on IRS Form 8582. If any "at risk" losses are involved (not typical for me) then IRS Form 6198 will also be used in calculating the carry forward loss.
Now-a-days it's becoming not all that common for a residential rental property owner to actually have carry forward losses. A few years back things were changed to where if you meet certain criteria, you can deduct up to $25K of your passive losses from other ordinary income. The TTX program deals with this automatically just fine, in my experience.
