Hi, This issue was raised in the MPICH GitHub https://github.com/pmodels/mpich/issues/5413. In MPI-3.1, we have C bindings for: int MPI_Get_elements(const MPI_Status *status, MPI_Datatype datatype, int *count) int MPI_Get_elements_x(const MPI_Status *status, MPI_Datatype datatype, MPI_Count *count) int MPI_Status_set_elements(MPI_Status *status, MPI_Datatype datatype, int count) int MPI_Status_set_elements_x(MPI_Status *status, MPI_Datatype datatype, MPI_Count count) MPI-4.0 added: int MPI_Get_elements_c(const MPI_Status *status, MPI_Datatype datatype, MPI_Count *count) But no binding was added for an _c version of MPI_Status_set_elements. Was this intended? Thanks, Ken