Multiyear Procurement (MYP) and Block Buy Contracting in Defense Acquisition: Background and Issues for Congress [Updated April 30, 2019] [open pdf - 1MB]
From the Introduction: "This report provides background information and issues for Congress on multiyear procurement (MYP) and block buy contracting (BBC), which are special contracting mechanisms that Congress permits the Department of Defense (DOD) to use for a limited number of defense acquisition programs. Compared to the standard or default approach of annual contracting, MYP and BBC have the potential for reducing weapon procurement costs by a few or several percent. Potential issues for Congress concerning MYP and BBC include whether to use MYP and BBC in the future more frequently, less frequently, or about as frequently as they are currently used; whether to create a permanent statute to govern the use of BBC, analogous to the permanent statute that governs the use of MYP; and whether the Coast Guard should begin making use of MYP and BBC. Congress's decisions on these issues could affect defense acquisition practices, defense funding requirements, and the defense industrial base."
CRS Report for Congress, R41909
Congressional Research Service: https://crsreports.congress.gov/