==No, a US provisional patent application does not have to be in Word (.doc or .docx) format==. While the USPTO is increasingly requiring DOCX format for certain non-provisional utility applications, this requirement does not apply to provisional patent applications. Provisional applications can still be filed in PDF format without incurring a surcharge.  Here's a more detailed breakdown: - **DOCX Requirement:** The USPTO's requirement to file in DOCX format applies to new non-provisional utility applications filed on or after January 1, 2023. This includes various types of non-provisional applications, such as continuations, divisions, etc.  - **Provisional Application Flexibility:** Provisional applications, including the specification and drawings, can be filed in PDF format.  - **No Surcharge for Provisional Applications in PDF:** If you choose to file your provisional application in PDF format, you will not be assessed the additional filing fee surcharge that applies to non-provisional applications filed in PDF.  - **Application Data Sheet (ADS):** For both provisional and non-provisional applications, the USPTO encourages the use of an Application Data Sheet (ADS) (or its equivalent) to provide essential bibliographic data. The ADS can be filed in PDF format, and it is separate from the main body of the application.