We present the development of a hermetic shield packaging enclosure for RF microelectromechanical system switches (MEMS) using Liquid Crystal Polymer (LCP). A cavity formed in LCP has been laminated, at low temperature, onto a Si MEMS switch to create a hermetically sealed package. The hermetically sealed enclosure is a stack-up layer of the multi-layer organic chip-on-flex system-on-a-package (SOP). The entire SOP hermetically sealed package has a total insertion loss of ∼0.5 dB at X-band. E595 outgas tests demonstrate that the LCP package is reliable and hermetically protects the MEMS switch.