Yeah, TurboTax Desktop does let you fill out a 3115 in forms mode. But as you mentioned, providing the attached statements is the challenging part. You could paper file your whole return and attach the statements to that. Or if you want to e-file, which is probably a better choice, you can then mail in a Form 8453 to submit the Form 3115 attachments to the IRS by mail separately from the e-filed return. And then, as you mentioned, you do also have to mail a copy of the Form 3115 to the IRS as well, as explained in the instructions for that form.
I haven't experimented with what TurboTax does when you put in a past placed in service date for an asset, but I would imagine it would just compute the current year depreciation.
David O
