You can join NACC by adding Communication Centers Section as an NCA affiliation. Just fill out this form and mail it to:
NCA National Office
1765 N Street, NW
Washington, DC 20036
Or, Justin Danowski—the NCA Membership Manager—can add "Communication Centers" as your NCA interest group. Most members call his direct line (202.534.1108) and give him their credit card information over the phone. Or, you can contact him via email at jdanowski@natcom.org.
The phone call takes less than five minutes, and Justin can send you a receipt via email after the order has been completed. There is a $5 fee.