Rapid Fielding Defense Capabilities and Risk Assessment Act This bill addresses the use of "middle tier" defense acquisition programs. It requires the Department of Defense (DOD) to brief Congress on lessons learned and best practices identified through the use of the middle tier of acquisition programs intended to be completed in a period of two to five years, using two pathways: rapid prototyping and rapid fielding. An analysis shall accompany the briefing that includes (1) identification of lessons learned that can be applied to both middle tier and major acquisition programs, (2) description of the extent to which covered risk (determined by DOD) should be a factor in determining acquisition authority, and (3) description of whether requirements applicable to major defense acquisition programs should be applicable to middle tier programs.