We report the structural, magnetic, and magnetocaloric characterization of glass-coated Ni_42.9Mn_37.1Sn_20.0 microwires produced by the Taylor-Ulitovsky method. Microwire samples crystallized into a single-phase austenite with the L2₁-type crystal structure (space group [Formula: see text], lattice parameter a ≈ 6.02 Å) and a Curie temperature of 349 K. A distinctive feature of the produced microwires is that saturation magnetization is reached at a very low magnetic field (∼0.15 T). For a magnetic field change of 3 T, the produced microwires showed a reversible maximum magnetic entropy change |Δ S_M|^max of 2.3 J kg⁻¹ K⁻¹ and a refrigerant capacity of 197 J kg⁻¹, which are similar to the values reported by other austenitic NiMnSn alloys produced by rapid quenching techniques.