Two previously unrelated employers maintained 401k plans which are merged 6/1.

Plan X was merged into Plan Y effective 6/1.

If I plan on testing Plan X separately from 1/1 - 5/31, do I need to prorate my 415 compensation limit?
Additionally Plan X is audited, but there appears to be an exception to the audit requirement when a short plan year is created due to a merger which is less than 7 months. Is this true? I understand Plan Y will be audited for the full year.

Thanks

My memory of this issue is fuzzy, but I don't think the short year exception means Plan X doesn't need an audit. I think it just says the audit for the short year can be done in combination with either Plan X's previous or subsequent full year audit. Also, I think there has been some debate over the years whether Plan Y's audit for the year of the merger would be considered "Plan X's subsequent audit." I would think not.