I saw this posting on the USAC Facebook Page.
They are starting by offering a joint membership:
The joint membership is now available for purchase for $99, a $31 savings versus purchasing the two memberships separately. More details and a registration link can be found at usacycling.org and usatriathlon.org.
Also:
The organizations will cross-promote their respective National Championships and select sanctioned races to each other’s members in an effort to expand racing opportunities for both groups.