One example of layer-by-layer error correction can include iteratively error correcting the codeword on a layer-by-layer basis with the first error correction circuit in a first mode and determining on the layer-by-layer basis whether a number of parity errors in a particular layer is less than a threshold number of parity errors. The codeword can be transferred to a second error correction circuit when the number of parity errors is less than the threshold number of parity errors. The codeword can be iteratively error corrected with the first error correction circuit in a second mode when the number of parity errors is at least the threshold number of parity errors. The threshold number of parity errors can be at least partially based on an adjustable code rate of the first error correction circuit or the second error correction circuit.