The pool of memory T cells is regulated by homeostatic mechanisms to persist for prolonged periods at a relatively steady overall size. Recent work has shown that two members of the common γ chain (γc) family of cytokines, interleukin‐7 (IL‐7) and IL‐15, govern homeostasis of memory T cells. These two cytokines work in conjunction to support memory T‐cell survival and intermittent background proliferation. Normal animals contain significant numbers of spontaneously arising memory‐phenotype (MP) cells, though whether these cells are representative of true antigen‐specific memory T cells is unclear. Nevertheless, it appears that the two types of memory cells do not display identical homeostatic requirements. For antigen‐specific memory CD8⁺ T cells, IL‐7 is primarily important for survival while IL‐15 is crucial for their background proliferation. For memory CD4⁺ T cells, IL‐7 has an important role, whereas the influence of IL‐15 is still unclear.