  We present stellar mass fractions and composite luminosity functions (LFs)
for a sample of \Ncl\ clusters from the Massive and Distant Clusters of WISE
Survey (MaDCoWS) at a redshift range of $0.951 \leq z \leq 1.43$. Using SED
fitting of optical and deep mid-infrared photometry, we establish the
membership of objects along the lines-of-sight to these clusters and calculate
the stellar masses of member galaxies. We find stellar mass fractions for these
clusters largely consistent with previous works, including appearing to display
a negative correlation with total cluster mass. We measure a composite
$3.6~\mathrm{\mu m}$ LF down to $m^*+2.5$ for all 12 clusters. Fitting a
Schechter function to the LF, we find a characteristic $3.6~\mathrm{\mu m}$
magnitude of $m^*=19.83\pm0.12$ and faint-end slope of $\alpha=-0.81\pm0.10$
for the full sample at a mean redshift of $\bar{z} = 1.18$. We also divide the
clusters into high- and low-redshift bins at $\bar{z}=1.29$ and $\bar{z}=1.06$
respectively and measure a composite LF for each bin. We see a small, but
statistically significant evolution in $m^*$ and $\alpha$ -- consistent with
passive evolution -- when we study the joint fit to the two parameters, which
is probing the evolution of faint cluster galaxies at $z\sim1$. This highlights
the importance of deep IR data in studying the evolution of cluster galaxy
populations at high-redshift.
