quantum chemistry - Is the d-block ever part of the valence electrons?

The d-block sub-shell is always one shell lower than the s-block and p-block sub-shells. Assuming only the electrons in the highest energy shells count toward the set of valence electrons (is that correct?), d-block is never in the highest energy shell, and so none of the electrons in the d subshells would ever count toward the valence electrons.

I suspect I'm mistaken. Am I? If so, where have gone wrong?