Abstract: Two smooth knots are concordant when they mutually bound a cylinder. The symplectic version is called Lagrangian concordance and is a relation of Legendrian knots. We can ask: when is a Legendrian knot concordant to another? In this talk, I will define Lagrangian concordance and talk about what we know and don’t know about it. Time permitting, I’ll sketch one way to obstruct this relation for certain kinds of knots.