Written Description Requirements for a Provisional Patent Application

By: Savannah Johns 

Before filing a provisional patent application, make sure you understand the implications of Dental Monitoring SAS v. Align Tech., Inc., 184 F.4th 1376 (2026).  

The Federal Circuit Court of Appeals (“The Court”) vacated the USPTO Patent Trial and Appeal Board’s (“The Board”) decision that a provisional application filing date could qualify as an earlier filing date for claim priority, usable against prior art, as long as the provisional application satisfies the “ministerial requirements” of 35 U.S.C. §§ 119 and 120 and describes the subject matter of the invention. The Court held that a provisional application is not meant to merely demonstrate ministerial requirements in §§ 119 and 120, but additionally must provide a written description per the requirements of 35 U.S.C. § 112(a) to obtain the filing date of the provisional application to receive the date for priority.  

This decision applies to the PTO application requirements:  

1. Clear written description of the invention (describing materials, directions, and use) 

2. Name of inventors  

3. Address  

4. Invention Title  

5. Registration Number  

The first PTO application requirement follows the same language as the Court references in § 112(a). Essentially, at least one claim in the non-provisional must be supported with a written description of the invention in the provisional application containing clear, concise, and exact terms to enable any person skilled in the art to make and use the invention as described. Having this clear written description in the provisional allows a person with ordinary skill in the art to recognize that the inventor is in possession of what they are seeking to protect. The written description in the provisional application ideally should be just as detailed as the non-provisional specification. Accordingly, the level of disclosure in a provisional application must be seriously considered and reviewed prior to filing.