Sole proprietor incorporated: Keep old 401(k) or create new one?

[Guest hk73]

I'm confronted with this situation:

Sole proprietor established self-employed 401(k) in 2004, incorporated in 2005 (S-corporation). The 401(k) was established with Fidelity (prototype plan) with the TIN of the sole proprietorship as plan sponsor.

Questions:

* Keep the old 401(k) and contribute to it from the S-corp income?

* Let the old 401(k) sit there w/o new contributions and create a new 401(k)?

* Create a new 401(k) and roll over the old account to the new one?

What formalities have to be done, and what restrictions apply in each case?

[Bird]

Keep the same plan and change the sponsor from the sole prop to the corp. You'll need a corporate resolution saying that the corp is adopting the plan, and something from the sole prop saying it's OK...I sometimes just have the sole prop sign something on the corp resolution saying something like "yeah, this is OK by me."

Then you have to tell Fidelity. Good luck with that part...