diff --git a/planning/iris/iris_from_clique_cover.h b/planning/iris/iris_from_clique_cover.h
index 7357b34edad5..5dfadc260bed 100644
--- a/planning/iris/iris_from_clique_cover.h
+++ b/planning/iris/iris_from_clique_cover.h
@@ -109,6 +109,12 @@ struct IrisFromCliqueCoverOptions {
  * general use suboptimal cliques when constructing the greedy clique cover, but
  * is faster than solving the max clique problem to global optimality.
  *
+ * Currently, the padding in the collision checker is not forwarded to the
+ * algorithm, and therefore the final regions do not necessarily respect this
+ * padding. Effectively, this means that the regions are generated as if the
+ * padding is set to 0. This behavior may be adjusted in the future at the
+ * resolution of #18830.
+ *
  * Note that this method requires an implementation of a MaxCliqueSolverBase
  * which must be implemented in C++. The only solver of this kind implemented by
  * Drake is MaxCliqueSolverViaMip which requires the availability of a