How much does it cost to join a community in addition to the ones that come with my membership? KB Admin, ATD Updated October 14, 2016 19:23 Follow All ATD Professional members are able to select four communities. To join additional communities, there is a fee of $30 per community per membership year. ATD Professional Plus members have unlimited access to all of the communities’ content. Related articles What is a community of practice? Do I have to be an ATD member to join a community of practice?