  We present a 0.3--4.5 $\mu$m 16-band photometric catalog for the
Spitzer/HETDEX Exploratory Large-Area (SHELA) survey. SHELA covers a $\sim 27$
deg$^2$ field within the footprint of the Hobby-Eberly Telescope Dark Energy
Experiment (HETDEX). Here we present new DECam imaging and a
$rizK_s$-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 $riz \sim 24.7$ ($25.1$) AB mag, and the optical
photometry reaches a $5\sigma$ depth of $\sim 25.5$ AB mag. We measure
photometric redshifts and achieve $1\sigma$ scatter of $\Delta z/(1+z)$ of 0.04
with available spectroscopic redshifts at $0 \le z \le 1$. This large area,
multi-wavelength photometric catalog, combined with spectroscopic information
from HETDEX, will enable a wide range of extragalactic science investigations.
