Can anyone confirm that under 401(a)(9) that even rollover assets from outside plans (say a DC plan) rolled into a DB plan must still be paid out under the DB annuity method instead of the account balance method (I'm aware of the 2 year transition rule on reliance on prior proposed regs but I'm ignoring that for the moment). Thx.

A rollover account must be separately maintained, so I would consider it an individual account subject to the rules govening individual accounts. I have not researched it, it is just a reaction. I would not even bother to research it; it just seems like common sense. These rules are so convoluted anyways regarding the account balance method which never existed for DB plans. Talk about massive noncompliance.

Rollovers to a db are not part of the annual benefit. reg. 1-415-3(b).