My understanding is that nonconforming states cause headaches at the participant level and not so much at the plan level.
Here's a Q&A from the Technical Answer Group (
www.tagdata.com) that might be helpful:
Question:
State tax law and EGTRRA - I have heard that some of the states do not recognize the changes made by EGTRRA. Is this true, and what impact does it have? Should I advise clients not to incorporate the EGTRRA changes unless and until their state complies with EGTRRA?
Answer:
Most of the states automatically comply with changes to the federal tax code. However, there are some that do not. These states are referred to as nonconforming states. When there is an amendment made to the Internal Revenue Code, the nonconforming states must amend their state tax codes if they want to adopt the same tax provisions as are included in the amendment of the federal code. This is an area of particular interest with regard to the EGTRRA changes. For example, the nonconforming states do not automatically recognize the increased contribution limits under Code Section 415, the increased deferral limits under 402(g), the availability of catch up contributions, or the expanded rollover rules. Participants in these states can make catch up contributions, but the amount of the catch up contribution would be included in income for purposes of applying the state income tax. The same would hold true for the other EGTRRA changes.
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...even if the states do not amend to raise the deferral limits (or other EGTRRA changes), the changes will still apply for purposes of the federal tax code. While the changes may not be as advantageous in states that elect not to comply with EGTRRA, the affect on federal taxes is still significant. I would not make the decision to adopt or not adopt the EGTRRA changes based on state tax law."
I've never seen a plan disqualified at the state level. I don't think this is possible. Good Luck.