Partial methods enable separation of method declaration and/or calls from method implementation. A partial method specifies a signature of a join or hook point in a class. Calls to a partial method specify a join or hook point in code that can optionally be linked with an actual method implementation of the same signature. Separate method implementations or other code related to a partial method are injected into a single program prior to execution. Unimplemented partial methods are treated as no operation instructions or otherwise ignored.