Systems and methods disclosed herein provide an outer code for HARQ applications, which may be an erasure code. In some embodiments, the outer code has a relatively simple decoding algorithm, increased decoding probability with no extra redundancy packets needed and can correct an arbitrary number of code blocks. In some embodiments, the outer code may be implemented as part of the 5G air interface, also known as new radio (NR), and/or in applications such as vehicle-to-everything (V2X) and/or ultra-reliable low latency communication (URLLC). Some embodiments provide a nested HARQ protocol for HARQ transmission with an outer code.