To participate in most SCCA events, you'll need to either be a full member, or purchase a weekend membership. Keep in mind that some events like Time Trials Nationals and Solo Nationals require that you be a full member and do not allow weekend memberships. So, what's the difference? Here's a quick breakdown.

Full Membership Weekend Membership
Accepted at most Regional events
Accepted at all SCCA events
Partner discounts
Eligible for Licenses
Additional per-event cost $0 $10 – $50