Pay grade E6 through E8. After that, the enlisted rank structure has a few options. You can go into a more administrative line and become, for example, a First Sergeant or you can stay within your MOS and become, for example, a Master Gunnery Sergeant.
Staff NCOs are who run the military. The orders come from the brass up above but the Staff NCOs carry them out. A good Platoon Commander will listen to the advice of the Gunny and do what he suggests but the orders still have to come from an Officer.
On ship, Staff NCOs don't have to sleep in the berthing areas with the rest of the troops. They get an area between Officer Country and the bowels of the ship where the majority of the Non-rates are. Staff NCOs can get out of runs, humps and most patrols but a good one won't. They can talk back to an Officer but a good one will use tact. They can smoke and walk, be outside without a cover, show up to formation without ironing their uniform. They can miss a haircut and a shave and smell like beer. They can carry their rifle any goddamn way they feel like.
But a good one won't.
A good example of authority and responsibility but not very much accountability.