The 2015 nuclear physics long-range plan endorsed the realization of an Electron-Ion Collider (EIC) as the next large construction project after the completion of FRIB. With its high luminosity (> 10$^{33}cm^{−2}s^{−1}$), wide kinematic reach in center-of-mass-energy (45 GeV to 145 GeV) and high lepton and proton beam polarization, an EIC provides an unprecedented opportunity to reach new frontiers in our understanding of the spin and dynamic structure of nuclei. Despite of the success of the HERA collider in investigating the structure of a single nucleon, the partonic structure of nuclei at moderate-to-small Bjorken’s $x$ still remains elusive. We present the evaluated impact of an EIC in extracting the nuclear structure-functions from measurements of the reduced cross section in deep inelastic scattering, including also the case of measuring heavy quark production events. The potential constraints offered by the EIC data in extracting the nuclear parton distribution functions is also discussed.