The Alfvén Wave Solar atmosphere Model (AWSoM) and its realtime variant (AWSoM-R), the SWMF’s global model of the corona and solar wind, places its inner boundary in the upper chromosphere and injects Alfvén-wave Poynting flux through a thin, quasi-static chromospheric layer. As a result the partially ionized, radiatively cooled, dynamically evolving chromosphere — the reservoir that sets the mass and energy supplied to the corona — is prescribed rather than solved. We present a 1.5D field-aligned two-fluid (ion + neutral) chromosphere model, run along PFSS field lines, aimed at supplying this missing physics. The model evolves separate ion and neutral fluids coupled by collisional drag and two-temperature exchange, with field-aligned electron and neutral heat conduction, a physically grounded coronal upper boundary, and radiative cooling (optically-thick H I / Ca II / Mg II line losses plus optically-thin transition-region emission). Non-equilibrium hydrogen ionization and recombination — collisional, photoionization, and radiative/three-body channels — are integrated self-consistently. We report the resulting chromospheric ionization and recombination rates and their height structure, and demonstrate the model’s dynamics through a flare-driven explosive chromospheric evaporation case, recovering the characteristic upflow and condensation-downflow signatures. The framework is designed as a drop-in dynamic lower boundary for AWSoM-R.