Sponsor of a Simple 401(k) wants to amend to be
a "traditional" 401(k). They are not using the
Model Amendment (Rev. Proc. 97-9) but have an Adoption Agreement. Can they amend to a traditional 401(k) this year (protecting accruals), or do they have to wait until 1-1-02?

And since there's 100% vesting under a Simple (k),
do all existing participants have to remain 100% vested going forward, not only in existing Simple contributions, but in the new traditional (k) employer contributions too? There are discussions under the 401(k) section, that indicate the vesting schedule must follow the participant.

I don't think anyone knows for sure if you can switch midyear or not if you are not using the model documnet. ceratinly you can't if you were.
good grief, you only have 3 1/2 months left, I'm not sure how much of a difference it can make this late in the year.
I would think the vesting only accompanies the SIMPLE match or nonelectives that have been made. in other words the vesting follows the source, just like a QNEC - but the person is still subject to vesting in other 'traditional' contributions.

A SIMPLE 401(k) may be changed back to a traditional 401(k), but not any earlier than the first day of the next plan year.