  The notion of Lagrangian $H$-umbilical submanifolds was introduced by B. Y.
Chen in 1997, and these submanifolds have appeared in several important
problems in the study of Lagrangian submanifolds from the Riemannian geometric
point of view. Recently, the author introduced the notion of tangentially
biharmonic submanifolds, which are defined as submanifolds such that the
bitension field of the inclusion map has vanishing tangential component. The
normal bundle of a round hypersphere in $\mathbb{R}^n$ can be immersed as a
tangentially biharmonic Lagrangian $H$-umbilical submanifold in $\mathbb{C}^n$.
Motivated by this fact, we classify tangentially biharmonic Lagrangian
$H$-umbilical submanifolds in complex space forms.
