You are correct in that at Milestone B, the MDA ensures that the program is fully funded (Acquisition Program Baseline) for the remainder of the program, through the Operations and Support phase, and that the technology upon which realization of the needed capability is at a TRL 6, i.e., successfully demonstrated in a relevant environment using a prototype. Upon receiving approval of Milestone B by the MDA, the contract for the EMD phase and, in some cases, Low Rate Initial Production (LRIP), is signed and awarded to the contractor.

The Program Office is now established prior to Milestone B to address issues such as budgeting, scheduling, requirements development, and technology maturation, and to prepare for releasing the RFP prior to MS B. During Technology Maturation and Risk Reduction (TMRR), the Program Office ensures that the required technology has been demonstrated at a TRL 6 or better prior to entering Engineering and Manufacturing Development (EMD) phase at Milestone B. There are numerous ways to conduct technology maturation using any number or combination of sources including academia, private and government laboratories, and contractors. Contracting vehicles include Small Business Innovative Research (SBIR) and Small Business Technology Transfer (STTR), as well as funded Competitive Prototyping.  The funding is usually from Research and Development funds authorized by Congress. Prior to or just after Milestone A, the Program Office will solicit proposals from interested and capable contractors and will award one or more contracts to industry for a competitive prototype(s). Usually associated with these contracts is a requirement for the contractor(s) to conduct a Preliminary Design Review (PDR) of the prototype they developed and demonstrated under their contract. This provides the information needed to demonstrate that the proposed technology meets the requirements of TRL 6.