You need to login to the NAR website to see the "member resources" section that has a bunch of information about NAR insurance. I hope that I'm doing a better job at answering your question. Here are quotes from the NAR website:

My Section often has non-members attending our launch. Are they covered by NAR insurance when they fly with us?

Sometimes; generally, non-members are not covered by NAR insurance. To obtain coverage, they must join and become members of the NAR. However, your Section’s coverage and your individual NAR members’ coverage by the NAR insurance policy remains. However, students, whether NAR members or not, who are members of teams participating in national student rocketry events officially sponsored by the NAR (currently Team America Rocketry Challenge and the NASA Student Launch Initiative/University SLI program) are covered only when they fly at an organized NAR section launch—but not at other times and places.


Who is protected under NAR Section insurance?

Section liability insurance protects the group, corporately, against bodily injury and property damage claims during activities sponsored by the club. If the Section, as a group, is named in a legal action as a result of a rocket accident, the NAR liability policy would respond to the alleged damages, pay for the expenses resulting from the lawsuit, plus damages awarded. Individual members may still be held liable for their own actions. Some additional protection may be achieved if the club is a registered nonprofit corporation — contact an attorney in your state for guidance.

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-Wolfram v. Kiparski
NAR 28643 - TRA 15520
MTMA Section #606 President