Can CPC classification for a patent application change during examination?

This page is an FAQ based on guidance from the Manual of Patent Examining Procedure. It is provided as guidance, with links to the ground truth sources. This is information only: it is not legal advice.

Yes, the CPC classification for a patent application can change during examination. While MPEP 909.01(a) states that “New applications are classified in the CPC system” initially, the classification may be adjusted during the examination process. Reasons for changes include:

• Amendments to the claims that alter the scope of the invention
• Examiner’s improved understanding of the invention after detailed review
• Discovery of more appropriate CPC symbols during prior art searching
• Updates or changes to the CPC system itself

It’s important to note that while the initial classification is based on the application as filed, any significant changes to the claimed subject matter during prosecution may necessitate a reclassification. This ensures that the final classification accurately reflects the invention as claimed in the granted patent.