CoDA, or Codependents Anonymous, is a 12-step group
for working toward healthy relationships
with oneself and others.
It is based on the program of Alcoholics Anonymous, adapted to fit something that is basically an emotional pattern rather than a physical addiction. To some extent both codependency and alcoholism serve as addictions, in that the codependent is using other people rather than a drug in order to fill a hole inside themselves. However, the lack of physical withdrawal symptoms and the need to interact with people in a healthy manner rather than quitting them "cold turkey" are two major differences between the experiences of being alcoholic and codependent. (At the same time, codependent behavior is behind many addictions.)
According to http://www.codependents.org, CoDA's third tradition states that "The only requirement for membership is a desire for healthy and fulfilling relationships." Their program for recovering from codependency consists of four parts:
Attending meetings which vary by theme and purpose - there are meetings just for sharing, speaker meetings that have a main speaker share for all or some of the time, step meetings that focus on study and sharing around the steps, etc.;
Sharing & fellowship talking to other people in the program, sharing your experiences, learning from theirs, and finding out that you're not alone;
Sponsorship working with another CoDA member who has been working on these issues longer and can help you work the steps and provide support for the issues that come up for you - or being a sponsor for someone else; and
Working the steps which are a series of exercises in self-awareness and understanding how to find healthy solutions to life's problems.