408.41 Grounded Conductor Terminations.
Each grounded conductor shall terminate within the panelboard in an individual terminal that is not also used for another conductor.
No..in the enclosure that contains the service disconnect the neutrals and grounds can land on the same bar, but just not under the same screw.do the grounded and grounding conductors need to be physically isolated, meaning-- neutrals on one side and grounds on the other side?