This snippet will remove the black admin bar from the top of the window if the user is not an Administrator.
/**
* remove_admin_bar
*
* @return void
*/
function ibanner_remove_admin_bar_for_non_admins() {
if (!current_user_can('administrator') && !is_admin()) {
show_admin_bar(false);
}
}
add_action('after_setup_theme', 'ibanner_remove_admin_bar_for_non_admins');