A central characteristic of living organisms is their agency, that is, their intrinsic activity, both in terms of their basic life processes and their behavior in the environment. This aspect is currently a subject of debate and this article provides an overview of some of the relevant publications on this topic. We develop the argument that agency is immanent in living organisms. There is no life without agency. Even the basic life processes are an intrinsic activity, which we call the (...) organismic level of agency. In addition to this we describe several further levels. These capture different qualities that occur or transform during evolution. In addition to the organismic level, we propose an ontogenetic level, a level of directed agency, directed agency with extended flexibility, and a level that includes the capacities to follow preconceived goals. A further property of organisms is their autonomy. It has been shown that the capacity for autonomy changed during evolution. Here we propose that the two organismic properties autonomy and agency are closely related. Enhanced physiological and behavioral autonomy extends the scope of self-generated, flexible actions and reactions. The increase in autonomy through the evolution of a widened scope of behavioral possibilities and versatility in organisms coincides with extended levels of agency. Especially the human organization, including the sophisticated brain, is the basis for an extended level of agency referring to the capacities to follow preconceived goals. However, it is important for the understanding of the phenomenon of agency not only to assume this latter form, but also to look at the different levels of agency. (shrink)