The Electron-Ion Collider’s (EIC) Hadron Storage Ring (HSR) is to be repurposed from existing components from the Relativistic Heavy Ion Collider. The HSR will accelerate and store polarized protons from Gγ =45.5 to 525, and polarized helions from Gγ = 49.5 to 820. The required polarization is 70%, averaged over the duration of a store. Six Siberian snakes are used to maximize polarization up to these top energies. To facilitate longitudinal polarization at the interaction point, helical rotator magnets will be placed on either side of the IR. This presentation gives an overview of the HSR polarization, and relevant simulations.