We present a 0.3-4.5{mu}m 16-band photometric catalog for the Spitzer/HETDEX Exploratory Large-Area (SHELA) survey. SHELA covers an ~27deg^2^ field within the footprint of the Hobby-Eberly Telescope Dark Energy Experiment (HETDEX). Here we present new DECam imaging and an rizKs band-selected catalog of four million sources extracted using a fully model-based approach. We validate our photometry by comparing with the model-based DECam Legacy Survey. We analyze the differences between model-based and aperture photometry by comparing with the previous SHELA catalog, finding that our model-based photometry can measure point sources to fainter fluxes and better capture the full emission of resolved sources. The catalog is 80% (50%) complete at riz ~24.7 (25.1) AB mag, and the optical photometry reaches a 5{sigma} depth of ~25.5 AB mag. We measure photometric redshifts and achieve a 1{sigma} scatter of {Delta}z/(1+z) of 0.04 with available spectroscopic redshifts at 0<=z<=1. This large-area, multiwavelength photometric catalog, combined with spectroscopic information from HETDEX, will enable a wide range of extragalactic science investigations.