Is it possible to attach a schedule prepared by the taxpayer, when completing taxes on TurboTax?

[FusionPilot]

As a surviving spouse acquiring IRA accounts as beneficiary, there are important calculations that are not handled by TurboTax, including adjustment of basis in some IRA accounts. Can I attach a schedule (say from Excel) to explain manual adjustments?

[SusanY1]

TurboTax does not allow you to attach the schedule, and in most cases the IRS does not require that you submit documents when filing related to adjustments.  Often, attachments submitted that aren't specifically requested are ignored by the IRS. 

You can file by mail and attach them, if that is your preference.  However, we recommend that you keep the calculations and schedules with your own records and provide them only if the IRS specifically inquires about the issue at a later date.