We propose a systematic study of all observations of black hole and neutron star low-mass X-ray binaries (LMXBs) in the Spitzer archive. At least 125 unique LMXBs have now been observed with Spitzer, many as part of large Legacy surveys of the Galactic plane and bulge. This LMXB archive has remained largely unexplored. The proposed archival study builds on our recent analyses of the near-infrared and optical properties of LMXBs. With the Spitzer observations we will be able to constrain the dominant mid-infrared processes in various types of LMXBs as a function of X-ray spectral state. In particular we will focus on the properties of compact jets, with unique constrains on the power of jet outflows coming from mid-infrared data. The Spitzer mid-infrared data will be combined with our large archive of radio, near-infrared, optical, and X-ray data.