All I can say is in my region (Western North Carolina) they are not accepting any "private" pilots. In order to be part of an active mission we require the NIMS ICS100, ICS200, ICS300, ICS400 and to be a part of our team and participated in at least one training mission. We also require RPC.
Part of the reason for this is because we had so many people wanting to simply show up and fly (a missing person is reported on the news and they state where we have our IC set up) trying to help and they were lost from the get go. When the rubber hits the road we need to all be operating from the same play book as well as understanding the nomenclature being used otherwise we have a lot of wasted resources.
On the State level they are implementing a UAS group that can show up to large events and provide support.
Locally we are working on budget #'s to buy the equipment and set up a county UAS department. When set up we will be working under Part 107 and a Public Safety designations. Once established we will self certify our pilots and be able to have trained pilots from each division (police, fire, EMS etc).
I should have been clearer - private UAS operations are going to require Part 107 RPC, registration with DPS, and insurance. We don't require the ICS course modules for any SAR volunteers except Field Coordinators (Incident Commanders) - those are optional, although encouraged.