The effects of the magnetic field on the shape memory behavior of -oriented metamagnetic NiMnCoIn shape memory single crystals were investigated. Thermal cycling under constant stress and magnetic field, and stress cycling under constant magnetic field tests were conducted to understand their magneto-thermo-mechanical behavior. It was observed that critical stress during the superelastic behavior increased and transformation temperatures decreased with the applied field. Under 9 T applied field, compared to all magnetic shape memory alloys, an ultrahigh magnetostress level of 71 MPa was observed during the stress cycling experiments and transformation temperatures were decreased by 16 degrees C during the thermal cycling under stress. (C) 2015 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.