CUORE is a ton-scale detector located in Gran Sasso National Lab in Italy that is searching for neutrinoless double beta decay in Te-130. Calibration of the detector is critical for understanding the energy response, particularly for the Q-value of the decay where we expect to see neutrinoless double beta decay. To perform this calibration, the Detector Calibration System (DCS) has been designed and built to perform this calibration in situ by uniformly irradiating 988 crystals simultaneously at ~10mK. In this talk, I will discuss recent results from a prior experiment CUORE-0 and will also present results from a recent demonstration of the DCS where we fully deployed and extracted the calibration sources from 300K down to base temperature.