With regard to Roth conversions, Form 8606 Part II is required to be completed for all conversions from a traditional IRA to a Roth IRA. Part I (which this question is about) is required to be completed only if the taxable amount of the Roth conversion cannot be determined on Part II alone because you have basis in nondeductible traditional IRA contributions and you still had funds in a traditional IRA at year-end.
