Patent prosecution is the back-and-forth between an applicant’s attorney and the United States Patent and Trademark Office (USPTO) to get to a granted patent.

Below is a summary of the application and prosecution stages.

Filing the Application

The process begins when a patent attorney prepares and files a patent application with the USPTO. This application describes the invention in detail and includes claims, which are the specific legal boundaries of what the applicant is seeking to protect. Think of the claims as drawing a fence around the invention. Everything inside the fence is protected.

Once the application is filed, it enters a queue to be reviewed by a patent examiner at the USPTO. This waiting period alone typically takes one to three years, depending on the technology area.

The Examiner’s Review

When the application reaches the front of the queue, a patent examiner reviews it. The examiner’s job is to determine whether the invention is eligible, new, useful, and not an obvious variation of something that already exists. They will search existing patents and published materials to compare against the disclosed invention.

More often than not, the examiner will not approve the application right away. Instead, they will issue what is called an office action, which is an official letter explaining why certain claims have been rejected or objected to.

Office Actions: What to Expect

Receiving an office action is normal and should not be alarming. Studies of USPTO data show that roughly 85 to 90 percent of applications receive at least one office action before a patent is granted. On average, applicants receive about two office actions before their application is either approved or abandoned.

When an office action is received, the attorney will review the examiner’s reasoning and prepare a written response. This response may argue against the examiner’s position, amend the claims to better define the invention, or both. The goal is to find a path to approval that still provides meaningful protection.

How Long Does It Take?

From filing to final approval, the average patent prosecution timeline is two to three years for most technology areas. Some fields, such as software and business methods, can take longer, sometimes four or more years. Fields like biotechnology and chemistry also tend to have longer timelines due to the complexity of the subject matter.

There are options to accelerate the process, which can bring the average examination time down to about six to twelve months for an additional fee.

What Happens at the End?

There are a few ways patent prosecution can conclude. The best outcome is a notice of allowance, which means the examiner has approved the application and the patent will be granted once the issue fee is paid. If, after multiple rounds of responses, the examiner continues to reject the application, there are options such as filing an appeal or continuing to engage with the examiner.

Once a patent is granted, if it is a utility patent, it is valid for 20 years from the original filing date, provided maintenance fees are paid at regular intervals.

Why It Matters to Work with an Attorney

Patent prosecution is a highly technical legal process. The language used in the claims will determine the scope of protection, and small wording choices can have significant consequences. An experienced patent attorney would understand how to navigate examiner rejections, craft persuasive responses, and protect as much of your invention as possible throughout the process.