I just found that GAMG seems to be hiding MG's parameters when -help is used. I have this code in my PCSetUp_GAMG: /* should be called in PCSetFromOptions_GAMG(), but cannot be called prior to PCMGSetLevels() */ ierr = PetscObjectOptionsBegin((PetscObject)pc);CHKERRQ(ierr); ierr = PCSetFromOptions_MG( pc ); CHKERRQ(ierr); ierr = PetscOptionsEnd();CHKERRQ(ierr); if (mg->galerkin != 2) SETERRQ(wcomm,PETSC_ERR_USER,"GAMG does Galerkin manually so the -pc_mg_galerkin option must not be used."); Which seems funky, but I think I cloned this or had some reason to put this here. And I set: pc->ops->setfromoptions = PCSetFromOptions_GAMG; in PCCreate_GAMG. Any advice on how I should fix this? Mark