If I rolled over pre-tax 401K money to an IRA, do I have to report this amount on line 6 of form 8606? Previously the 401K money was excludable. Should still be excluded.

[dmertz]

Yes, any money the IRA owner's traditional IRAs at year end must be included on Form 8606 line 6.  No, it cannot be excluded from line 6.

It's a relatively common mistake for individuals trying to execute a nontaxable "backdoor Roth" that the individual rolls money pre-tax over from a traditional 401(k) to an IRA, causing the Roth conversion that is part of the backdoor procedure to be largely taxable instead of tax-free and causing a large amount of the IRA owner's basis in nondeductible contributions to remain in the traditional IRA to be applied proportionately to future traditional IRA distributions.