What happens if a maintenance fee is not paid on time?

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.

Failure to pay a maintenance fee on time can result in the expiration of the patent. According to MPEP 2504:

“Unless the maintenance fee and any applicable surcharge is paid within the time periods set forth in paragraphs (d), (e) or (f) of this section, the patent will expire as of the end of the grace period set forth in paragraph (e) of this section.”

The patent will expire at the end of the same date (anniversary date) the patent was granted in the 4th, 8th, or 12th year after grant, depending on which maintenance fee was not paid.