The parallel realization of adaptive finite element methods (FEM) has to deal with several irregular and dynamic algorithmic properties caused by adaptive mesh refinement (AMR). For an implementation on distributed memory machines irregular communication behavior results from dynamically growing data structures and statically unknown communication partners. An efficient parallel implementation has to provide appropriate mechanisms to cope with the flexibility of the adaptive finite element approach at runtime. We have implemented a data management and communication layer for an adaptive, 3-dimensional, hexahedral FEM on distributed memory machines and use it to parallelize an existing sequential code. The data management and communication layer realizes duplicated data structures for boundaries of distributed data, additional hierarchical data structures to deal with uneven refinement, and coherence protocols to guarantee correctness of communication partners and messages. An easy...