Reimbursement for penalty mail service

§ 4156. Reimbursement for penalty mail service (a) Except as provided in subsections (b) and (c) of this section, executive departments and agencies, independent establishments of the Government, and Government corporations concerned shall transfer to the Post Office Department as postal revenue out of any appropriations or funds available to them, as a necessary expense of the appropriations or funds and of the activities concerned, the equivalent amount of postage due, as determined by the Postmaster General, for matter sent in the mails by or to them as penalty mail under authority of section 4152 of this title. (b) The Department of Agriculture shall transfer to the Post Office Department as postal revenues out of any appropriation made to it for that purpose the equivalent amount of postage, as determined by the Postmaster General, for penalty mailings under paragraphs (1) (F) and (4) of subsection (a) of section 4152 of this title. (c) The Library of Congress shall transfer to the Post Office Department as postal revenues out of any appropriations made to it for that purpose the equivalent amount of postage, as determined by the Postmaster General, for penalty mailings under paragraph (5) of subsection (a) of section 4152 of this title.