We attempt to expand the known population of millisecond pulsars (MSPs) and to add or modify their associations within the fourth Fermi catalog. MSPs are formed when a neutron star is spun up through the accretion of new material from a companion star. They are commonly found in globular clusters, because of the extremely high stellar density of these systems. We use 12 years of data collected by the Fermi Gamma-Ray Space Telescope to search for the cumulative signal from undetected MSPs in globular clusters. We employ a candidate list of 17 clusters that have ATNF pulsars within 0.3° of the cluster center and are not associated with a cluster in the Fermi catalog. Sources with low significance are then stacked together to extend the detection limit for sub-threshold populations.