Certain aspects of the present disclosure generally relate to wireless communications and, more particularly, to methods and apparatus for code rate selection for control channels. An exemplary method generally includes selecting, from a set of code rates, a code rate to be used to encode a stream of bits using a polar code, based on at least one of a downlink control channel aggregation size, an uplink control channel assignment, or a payload size of the stream of bits, encoding the stream of bits using the polar code and the selected code rate, and transmitting the encoded stream of bits.