In Part II paper (American Journal of Addictions, Vol 26, pages 67-74, this issue), we address how this literature informs a research program meant to develop and evaluate and stigma strategies (eg, education, contact, and protest). Both papers end with recommendations for next steps to jumpstart the addiction stigma portfolio. Here in Part I, we offer one possible list of key research issues for studies attempting to describe or explain addiction stigma. (Am J Addict 2017;26:59-66).