I have a client with a MP plan. My predecessor allocated contributions to eligible employees based on 1,000 hour service requirement. This is a standardized plan, as a result several participants did not receive contributions in prior years that should have possibly dating back to 1997. Based on the length of time passed, would it be best to restate the plan to a non-standardized document?

It may be best to switch to a non-standardized plan going forward if that meets the client's objectives, but it does nothing to clean up past sins.