Applicants and inventors work so diligently to put together the material and components of a patent application, that I often find it discouraging to explain the prosecution process after filing the application, because the only thing left to do is….wait; sit and wait and hope for a first action allowance or an Ex Parte Quayle action (in other words, notice from the Examiner that you are being granted your patent without any changes or with only minor modifications, of which we see very few).
After spending several thousand dollars on preparation of a patent application and U.S. Patent and Trademark Office (USPTO) filing fees, the question of “how long will it take” is at the top of all applicants’ list. The best and most reliable answer is to look at the USPTO Patent Dashboard website to look at the most relevant and recent average estimations.
Once the patent application has been filed, is pending, and has a Patent Application Serial Number, the time period following is called prosecution. Prosecution is where the application waits to be assigned to a Group Art Unit and an Examiner for review, along with the time the application is before the Examiner. The graph below shows that as of August 2015, it can take an average 17.5 months after the filing date to have a first action or correspondence from the USPTO regarding the application.

http://www.uspto.gov/corda/dashboards/patents/main.dashxml?CTNAVID=1004
Once the patent application is in the prosecution stage, the review process, including possibly several Office Actions and Amendments, can take on average 26.7 months until the patent is granted, as can be seen below.
