Modularity lifting theorems were introduced by Taylor and Wiles and formed a key part of the proof of Fermat's Last Theorem. Their method has been generalized successfully by a number authors but always with the restriction that the Galois representations in question have regular weight. Moreover, the sought after automorphic representation must come from a group that admits Shimura varieties. I will describe a method to overcome these restrictions, conditional on certain conjectures which themselves can be established in a number of cases. This is joint work with Frank Calegari.