  A $\mathcal{Z}$-structure on a group $G$ was introduced by Bestvina in order
to extend the notion of a group boundary beyond the realm of CAT(0) and
hyperbolic groups. A refinement of this notion, introduced by Farrell and
Lafont, includes a $G$-equivariance requirement, and is known as an
$\mathcal{EZ}$-structure. The general questions of which groups admit
$\mathcal{Z}$- or $\mathcal{EZ}$-structures remain open. In this paper we add
to the current knowledge by showing that all Baumslag-Solitar groups admit
$\mathcal{EZ}$-structures and all generalized Baumslag-Solitar groups admit
$\mathcal{Z}$-structures.
