Methods and apparatus are provided for block and rate independent decoding of LDPC codes. The disclosed LDPC decoders support multiple code block lengths and code rates, as well as a variable parity check matrix. The disclosed LDPC decoders decode LDPC codes that are based on a parity check matrix having a plurality of sub-matrices, wherein each row and column of the plurality of sub-matrices has a single entry. Each of the sub-matrices has at least one associated Phi-node, wherein each Phi-node comprises a memory device having a plurality of memory elements, wherein one or more of the memory elements may be selectively disabled. The Phi-nodes may be selectively disabled, for example, at run-time. The Phi-node optionally further comprises a multiplexer in order to provide a variable parity check matrix.