A computer-implemented method for termination of programs associated with different addressing modes includes receiving a call to an external interface to execute a target callee program from a caller program executing in a primary runtime environment. The external interface allocates an interoperability term area (ITA) in a primary runtime environment. The ITA is accessible by the primary runtime environment and a secondary runtime environment. The external interface executes the target callee program in the secondary runtime environment. The target callee program sets a termination reason parameter in the ITA. In response to the target callee program setting the termination reason parameter, a termination action in the primary runtime environment is performed. Various other methods, systems, and computer-readable media are also disclosed.