Final denial of an administrative claim under this subpart shall be
in writing, and notification of denial shall be sent to the claimant, or
his or her attorney or legal representative by certified or registered
mail. The notification of final denial shall include a statement of the
reasons for the denial and shall include a statement that, if the
claimant is dissatisfied with the Department's action, he or she may
file suit in an appropriate U.S. District Court not later than 6 months
after the date of mailing of the notification.