All COBOL to Fortran ILC applications require a relink except those containing OS/VS COBOL or VS COBOL II programs that were compiled with the NORES compiler option. If an OS/VS COBOL program is relinked, it cannot call or be called by a Fortran routine; the OS/VS COBOL program would need to be upgraded.

Fortran provides a migration tool that replaces old library modules with Language Environment ones. For more information about Fortran's library module replacement tool, see z/OS Language Environment Programming Guide.