A search for physics beyond the Standard Model (SM) is performed in events with final states including hadronic activity, missing energy, and significant momentum imbalance as measured with the MT2 variable. The results are based on data collected by the Compact Muon Solenoid detector at the Large Hadron Collider, and correspond to a total integrated luminosity of 35.9fb−1 of proton-proton collisions at a center-of-mass energy of 13TeV. No significant excess above the predicted SM background is observed. The results are interpreted as 95% confidence-level exclusion limits on the masses of hypothesized particles in a variety of simplified models of R-parity conserving supersymmetry (SUSY). Additional techniques for extending the search to target final states with low-momentum leptons is discussed, interpreted in in the context of SUSY models with compressed mass spectra, and compared to the exclusion strength of a typical all-hadronic search targeting such models.