Can a 5% owner take out his entire balance from a PS plan prior to termination if he is over 70 1/2?

Yes, if the plan is properly designed and drafted.

Thanks for the reply.

Plan doc. allows for hardship and in-service. The distribution request is for a hardship distribution. Are there specific aspects that should be defined in the plan doc?

Thanks

Assuming the the plan has appropriate hardship distribution provisions and the facts fit them, the 5% ownership does not require special consideration. Sounds like an odd situation, though.