Groundwater is an important water source for evaporation, especially during dry conditions. Despite this recognition, plant access to groundwater is often neglected in global evaporation models. This study proposes a new, conceptual approach to incorporate plant access to groundwater in existing global evaporation models. To this end, the Global Land Evaporation Amsterdam Model (GLEAM) is used, and the resulting influence of groundwater on global evaporation is assessed. The new GLEAM-Hydro model relies on the linear reservoir assumption for modelling groundwater flow, and introduces a transpiration partitioning approach to estimate groundwater contributions. Model estimates are validated globally against field observations of evaporation, soil moisture, discharge and groundwater level for the time period 2015-2021, and compared to a regional groundwater model. Results indicate only mild improvements in evaporation estimates, as most eddy-covariance stations are located in energy-limited regions or regions with no plant access to groundwater. The temporal dynamics of the simulated evaporation improves across 75% of the stations where groundwater is a relevant water source. The skill of the model for variables such as soil moisture and runoff remains similar to GLEAM v3. Representing groundwater access influences evaporation in 22% of the continental surface, and it increases evaporation globally by 2.5 mm year^-1 (0.5% of terrestrial evaporation). The proposed approach enables a more realistic process representation of evaporation under water-limited conditions in satellite-data driven models such as GLEAM, and sets the ground to assimilate satellite gravimetry data in the future.