Patent applications are filed to protect inventions. Obtaining a patent gives the owner a 20-year right to exclusive use, production, sale and marketing of the invention. A “continuation-in-part” application (“CIP”) is a subsequent application filed with the United States Patent and Trademark Office (“USPTO”), which adds one or more additional subject matters which were not disclosed in the original parent application. A CIP application is often filed because, after the parent application is filed, improvements are made and/or additional uses for the invention are found. Filing a CIP application is one option for capturing any improvements or new uses. To be eligible, a CIP application must share at least one inventor with the parent application and repeat a good part of the parent application’s specification. A CIP application may also include materials that enhance or elaborate on the claims in the parent application — such as additional detail, more descriptions or results of experiments. For these reasons, CIP applications can be convenient.

However, there are some disadvantages and, other than some minor cost savings, a CIP application has no advantages over filing a new patent application. Here are three reasons an inventor should not file a CIP application.

Differing Priority Dates and Shortened Patent Term

Some mistakenly believe that filing a CIP application will provide an earlier priority date for all claims. However, new claims in the CIP application will receive a priority date based when the CIP application was filed, while claims in the parent application will have the priority date of that application. For example, if the parent application sets forth and describes claims 1 through 5 and the CIP application adds claims 6 and 7, only the first five will have the parent’s priority date. Despite having a later priority date, if accepted by the Patent Office and if a patent is issued, all claims will only be entitled to 20 years of protection based on the date of the parent application. The shortened patent term is problematic particularly if the CIP application is filed some years after the parent application. It is preferable to file a new patent application.

Parent Application Can be Used to Limit the CIP Claims

Another problem with CIP applications is that, generally, any arguments and statements articulated in the parent application will be used to narrowly interpret the claim language in the CIP application. Sometimes this does not matter. But filing a separate patent application can avoid this potential downside.

Parent Application Can be Used as Prior Art

Another reason that CIP applications are no better than new independent patent applications is that, if more than a year intervenes between the parent and the CIP application, nothing prevents the disclosures in the parent application from being used as prior art for new claims in the CIP application. As one court stated the issue: “… the CIP application and its children become vulnerable to rejections based on a larger pool of prior art — including former parent applications in some cases.” See Natural Alternatives Intern’l, Inc. v. Iancu, 904 F. 3d 1375 (Fed. Cir. 2018); see also Santarus, Inc. v. Par Pharm., Inc., 694 F.3d 1344 (Fed. Cir. 2012). When this happens, the greatest vulnerability is rejection on the basis of obviousness.

As can be seen, CIP applications provide no particular benefit over filing an independent patent application and have several disadvantages.

For more information or if you have an invention that you want to patent, contact the patent lawyers at Revision Legal at 231-714-0100.