Starting in November 2000, the USPTO started publishing patent applications 18 months after their earliest filing date. So the simple assumption is that you file a patent and 18 months later it get publicized, right? Well, things aren’t that straightforward.
First of all, the “earliest filing date” really means the priority date since the US moved to a first-to-file system, so it’s really 18 months after the earliest priority date (including foreign filings). Also, the patent application can be filed up to 12 months after the invention is first sold into the market or otherwise disclosed (which becomes the priority date), so an application that take advantage of the 12-month grace period could be published as early as 6 months after filing.
There are also lots of exceptions to the 18-month rule: A filer can request early publication (because in some cases you can now claim pre-issue royalties if the patent is granted); the filer can elect to not file for foreign patents and request non-publication at the time of filing to prevent the filing from being published in the US; provisional applications are not published and remain secret; continuation-in-part and divisional applications based on years-old patent applications can be published within a few weeks of filing; the patent filer can request non-publication or the government can prevent publication due to national security reasons; etc.
In practice, the graph below shows that over half of US patent applications are published within a year after they were filed. The analysis below is based on the patents published in June 2015, based on how many months passed between when they were filed and when they were published:
There are several “spikes” in the data:
- The patents published at 3-month and 4-month are mainly divisionals and continuation-in-part and early-publish requests that are published as soon as they’re fully processed by the USPTO system.
- The most frequent publishing delay is 6 months – these are patents that were filed 12 months after the priority date.
- The 18-month spike is the case where the priority date is the same as the filing date for a new application, and the vanilla 18-month rule applies.
- The increase at 23 and 24 months is due to applications that are first filed as international applications (either in a foreign country or via a PCT application with WIPO) to preserve the international priority date, then later are filed with the US. The USPTO filing date is set to the earlier WIPO filing date rather than the later US filing date (the “371 Date”) of the US application.
So the simple 18-month concept turns out to be pretty complex and usually incorrect, since on average patent applications are published well before the 18-month delay.
Based on the analysis of the patents published in June 2015, fully 55% of patent applications are published within 12 months of filing. This actually makes patents more similar than you’d expect to journal articles, which typically take 3-9 months after submission to be published.