What limitation exists for new subject matter in a Continuation-in-Part application?

In a Continuation-in-Part (CIP) application, new subject matter added after the filing of the parent application is not entitled to the priority date of the parent application. This is key because any new claims based on that newly introduced subject matter will be assessed based on their own filing date, rather than inheriting the earlier filing date from the parent application. The priority date of the parent only applies to the claims that are fully supported by that previous application’s disclosure.

This limitation underscores the importance of the original filing date in establishing novelty and non-obviousness. If new subject matter is introduced, it must stand on its own merits, not drawing from the earlier priority date. This principle ensures that any claims reflecting the additional subject matter meet all requirements as they are treated as separate from the original claims filed in the parent application.

In contrast, options that imply new claims can always use the parent's filing date, that unlimited new claims can be introduced, or that there are no limitations as long as it claims to the parent misrepresent the boundary defined by patent law regarding continuity and new subject matter in CIP applications.