A bill to amend title 39, United States Code, to prohibit any increase in second-class mail rates and certain fourth-class mail rates for a 5-year period.

Prohibits the increasing, during the one-year period beginning on the date of enactment of this Act, of second-class rates of postage and the special fourth-class rates of postage for books, periodicals, and similar matter, as in effect on June 1, 1975.

Provides that at the beginning of each one-year period beginning immediately after such period following enactment, the Secretary of Labor shall certify to the Governors of the United States Postal Service the percent difference between the price index for the 12 months preceding each such one-year period and the price index for the base period.

Requires the Governors to increase such second-class rates and special fourth-class rates by such percent difference as reported. Provides that such increased rate shall be the rate in effect for such one-year period.

Defines the terms used in this Act. Defines the term "base period" as meaning the calendar year beginning January 1, 1975.