This summary describes research estimating the impact of changes in unit manning on soldiers’ individual readiness within battalion-sized units of the Army National Guard (ARNG) during periods of foundational readiness (when soldiers are not mobilized for deployment, on deployment, nor recently returned from deployment). The analyses focus on full-time support from soldiers authorized under Title 32 of the United States Code to serve in the Active Guard or Reserve (AGR). IDA quantified the relationship between the individual readiness of drilling soldiers and full-time support from Title 32 AGR soldiers. The goals were to understand payoffs to personnel investments, and to help ARNG leaders more effectively allocate full-time Title 32 AGR support to generate and maintain personal readiness across ARNG battalions. Using an innovative individual-level econometric framework, we found that Title 32 AGR support has a persistent, robust, positive effect on personal readiness levels, with the greatest estimated readiness impact of an additional Title 32 AGR soldiers in units where Title 32 AGR soldiers are scarce.