A modular particle-continuum method is extended to include vibrationally excited energy modes to simulate hypersonic steady-state flows that exhibit small regions of translational nonequilibrium in a mainly continuum flowfield. This method loosely couples an existing direct simulation Monte Carlo code to a Navier–Stokes solver (computational fluid dynamics) while allowing both time step and cell size to be completely decoupled between each method. A new information-transfer scheme that controls the inherently large statistical scatter of vibrational energies in low-temperature regions is described and tested. Two vibrational-relaxation models are implemented to test the sensitivity in agreement between direct simulation Monte Carlo and the modular particle-continuum method.By limiting the size of the direct simulationMonteCarlo region to only areas in translational nonequilibrium andmaintaining consistent physicalmodels in both computationalfluid dynamics anddirect simulationMonteCarlo modules, the modular particle-continuummethod is able to reproduce full direct simulationMonte Carlo results for flowwith globalKnudsen number of 0.01while decreasing the computational time required by a factor of about four.