This chapter advances SDG 6, 12, and 13 by explaining the Gravity Recovery and Climate Experiment (GRACE) and GRACE Follow On (GRACE-FO) missions that have greatly benefitted the modeling and monitoring of groundwater storage changes and drought at the global scale. In this chapter, we first review environmental controls on the temporal variability of groundwater using in situ data. We then describe an approach that infuses GRACE and GRACE-FO observations into a land surface model for assessing groundwater storage changes and drought globally.