This paper describes an improved matrix converter (MC) commutation process. The paper reviews existing commutation methods including the overlap and dead-band approaches and then two-, three- and four-step commutation processes. Their limitations are discussed and an improved four-step commutation process is proposed. The paper categorises switches as one or two active devices, or degree of freedom (DOF), implementations. The paper focuses on a two degrees of freedom SiC MOSFET switch for a four by four generalised MC implementation. The commutation process is summarised using two- three- and four-leg state machine diagrams. Experimental results are presented for Si-based MOSFETs and SiC-based MOSFETs switches using the four-step two-leg commutation process.