This article describes the development of an “Index” for assessing Alcoholics Anonymous (A.A.) affiliation during early recovery, i.e., the first three months after discharge from structured treatment. Analysis of participants' (N = 55) involvement in A.A. practices and acceptance of A.A. tenets yielded 16 items that embody both the fellowship and program dimensions of A.A. Rank-order comparison of affiliation “score” with number of meetings attended suggests that the Index reflects affiliation status more completely than meeting attendance alone. The Index is intended primarily as a tool for practitioners working with clients who may be candidates for A.A., but may also be useful to researchers seeking to develop more valid ways to measure client connections to A.A.