39 U.S.C. § 3214

Mailing privilege of former President; surviving spouse of former President

A former President and the surviving spouse of a former President may send nonpolitical mail within the United States and its territories and possessions as franked mail. Such mail of a former President and of the surviving spouse of a former President marked “Postage and Fees Paid” in the manner prescribed by the Postal Service shall be accepted by the Postal Service for transmission in the international mails.

( Pub. L. 91–375 , Aug. 12, 1970 , 84 Stat. 754 ; Pub. L. 93–191, § 4(a) , Dec. 18, 1973 , 87 Stat. 742 ; Pub. L. 103–123, title IV, § 6(b) , Oct. 28, 1993 , 107 Stat. 1246 ; Pub. L. 105–61, title IV, § 409(b) , Oct. 10, 1997 , 111 Stat. 1299 .)