Under the law in the U.S., inventors may file several different types of patent applications to cover new improvements to their inventions or to cover different aspects of their inventions. These types of patent applications include "continuation", "divisional", "continuation in part", and "reissue".
Continuation A "continuation application" is a patent application filed by an applicant who wants to pursue additional
claims to an
invention disclosed in an earlier application of the applicant (the "parent" application) that has not yet been issued or abandoned. The continuation uses the same specification as the pending parent application, claims the priority based on the filing date of the parent, and must name at least one of the inventors named in the parent application. This type of application is useful when a
patent examiner allowed some, but rejected other claims in an application, or where an applicant may not have exhausted all useful ways of claiming different embodiments of the invention. During the prosecution of a continuation application, the applicant may not add additional disclosure to the specification. If the inventor needs to supplement the disclosure of the earlier parent application, he has to file a continuation-in-part application.
Request for continued examination (RCE) In the typical case, a patent examiner will examine patent claims and amendments in an original patent application for two rounds of "office actions" before ending examination. However, often two office actions are not enough to resolve all of the issues in the
patent prosecution. A request for continued examination (RCE) is a request by an applicant for continued prosecution after the patent office has issued a "final" rejection or after prosecution "on the merits" has been closed (for example by a Notice of Allowance or by a Final Rejection). An RCE is not considered a continuing patent application - rather, prosecution of the pending application is reopened. The inventor pays an additional filing fee and continues to argue his case with the patent examiner. No RCE was allowed prior to June 8, 1995.
QPIDS program Because of a large number of last-minute Requests for Continuing Examination (RCEs) due to new
prior art being found, and the additional burden these RCEs impose on examination, the USPTO launched in May 2012 the Quick Path Information Disclosure Statement (QPIDS) Pilot Program. The program can be used to submit an
Information Disclosure Statement (IDS) during the time interval after payment of the issue fee but prior to patent grant. Only if the examiner feels that the references on the IDS are material, a Request for Continuous Examination is executed and examination is reopened. Prior to QPIDS program, launching a full-scale RCE was the only option to introduce new prior art during that time interval. Filing a QPIDS request requires a payment of full RCE and IDS fees, which are refunded, if no RCE is opened. However, QPIDS petition fee is not returned. Ca. 2018 the QPIDS program became permanent, even though USPTO's own study in 2014 showed very low applicants' participation rate.
Divisional A divisional application also claims priority based on the filing date of the parent application, but differs from a continuation application in that a divisional application claims a distinct or independent invention "carved out" of the parent application. A divisional application must share at least one of the inventors named in the parent application. A divisional application is often filed after the examiner issued a "restriction requirement", because a patent can only claim a single invention (cf.
unity of invention). The
USPTO practice of splitting patent applications into numerous divisionals has been criticized as an abuse intended to increase the USPTO revenues at the expense of patent holders.
Continuation-in-part (CIP) A "continuation-in-part" application ("CIP" or "CIP application") is one in which the applicant
adds subject matter not disclosed in the parent patent application, but repeats a substantial portion of the parent's specification, and shares at least one
inventor with the parent application. The CIP application is a convenient way to claim enhancements developed after the parent application was filed. It is the successor to the earlier "additional improvement" patents mentioned above. For a continuation-in-part application, claims to subject matter that was also disclosed in the parent are entitled to the parent's priority date, while claims to the additional subject matter are only entitled to the filing date of the CIP application. A reissue patent has the
kind code E. ==Controversy around attempted changes by USPTO to continuation practice==