A bill to provide for quarterly adjustments in the support price of milk.

Amends the Agricultural Act of 1949 to establish the price support of milk at not less than 90 percent of the parity price therefor beginning at the start of the new marketing year. Requires semiannual adjustments but authorizes quarterly adjustments when there are sharp increases in the index of prices paid by farmers. Directs the Secretary of Agriculture to establish a sell-back price at a level high enough to encourage holding of stocks by the private sector rather than the Commodity Credit Corporation.