Last I heard (the beginning of June), the 2016 US Multihull Championship for the Hobie Alter Trophy will be sailed in Hobie 18s on Lake Carlyle, IL, August 22-26, 2016 in conjunction with the Hobie 17 North Americans.

The event's been approved by the HCANA, but I don't know if it's been formally approved by US Sailing yet. I don't see any reason why it wouldn't be.