NO$\nu$A is a long-baseline off-axis beam neutrino experiment. By measuring $\nu_\mu$ disappearance and $\nu_e$ appearance at the 14 kiloton NO$\nu$A Far Detector, the experiment is addressing outstanding questions in neutrino physics, including the neutrino mass hierarchy and existence of leptonic CP violation. The NO$\nu$A Test Beam program, under deployment at the Fermilab Test Beam Facility, will use a scaled-down NO$\nu$A detector to sample beams of tagged electrons, muons, pions, and protons in the momentum range of 0.3 to 2 GeV/c. It will further the NO$\nu$A physics reach by precisely measuring the detector's muon energy scale and electromagnetic and hadronic response, and provide real data for detailed studies of particle identification techniques. Ongoing efforts on beam-line instrumentation, data acquisition, simulation, momentum reconstruction and particle identification are presented. Implications for the neutrino oscillation measurements are discussed.