During the last decade, the role of MRI in radiation therapy (RT) grew dramatically. The soft-tissue benefits from MRI simulations complement the geometric accuracy and photon attenuation maps from computed tomography in RT treatment planning. MR for calculating attenuation (MRCAT) is being used for MRI-only treatment planning. The clinical utilization of hybrid MRI-guided radiation therapy (MR-IGRT) systems began in January 2014. MR-IGRT enables real-time tracking of tumors and highly conformal treatments that enable improved patient outcomes. Hence, the value of MRI in RT is rapidly rising. Examples of MRI's role in, and value to, RT are presented.