DB w/414k account

[JAY21]

I have a client that wants to roll an old SEP-IRA into his DB plan that he is actively funding at high levels. His main motive for doing this is to invest in a broader range of investments than can easily be done through an IRA (yes, I'm aware of some of the self-directed IRAs out there but he wants to do it this way). Some of the investments he wants to do from the SEP rollover seem to have high return potential and if that occurs I don't want the investment performance to impact the DB funding which I believe it would if I just used a "pooled" approach and allocated earnings pro-rata. Is this a good situation for a 414k account where the SEP-IRA rollover funds get separately tracked and investment returns tied specifically to that account ? I do realize we could put in a new frozen MP plan and maybe roll into that and accomplish the same thing.

[SoCalActuary]

I would see no problem with the rollover of the SEP into the DB plan.

Your accounting issue after it's done... that's more complex.

If you run two separate trust accounts, with no commingled funds, then no problem.

If not, how do you separately track the investment performance of each source of funds? When new purchases are made, how do you track which source's funds are applied to it? When investment returns come in, where is the fund reinvested?

If you solve those, then certainly you should do what you intend.