PTA Calculation: How to Calculate Patent Term Adjustment

Patent term adjustment (PTA) is a mechanism designed to compensate patent owners for delays that occur during the patent examination process. It extends the duration of a patent beyond its standard term to account for certain administrative delays. PTA calculation involves specific steps and considerations to accurately determine the adjusted term. In this article, we will guide you through the process of calculating patent term adjustment.

1. Determine the Start of the Patent Term

The first step in calculating PTA is to establish the start of the patent term. The start date is typically the filing date of the patent application. However, certain events, such as a continuation application or a request for continued examination (RCE), may impact the start date. It is crucial to identify the correct start date to ensure accurate PTA calculation.

2. Identify the Three Types of Patent Term Adjustment

PTA consists of three components: A-Delay, B-Delay, and C-Delay. Understanding these components is essential for calculating the total PTA.

2.1 A-Delay: Applicant-Related Delays

A-Delay accounts for delays caused by the patent applicant during the patent examination process. It includes time periods such as:

  • The time taken by the applicant to respond to office actions.
  • The time taken to request continued examination.
  • The time taken to file a supplemental examination.

2.2 B-Delay: Patent Office Delays

B-Delay compensates for delays caused by the United States Patent and Trademark Office (USPTO) during the examination process. Examples of B-Delay factors include:

  • The USPTO failing to provide a first office action within 14 months of filing.
  • The USPTO failing to issue a patent within three years of the application’s filing date or the patent’s issue date, whichever is later.

2.3 C-Delay: Administrative Delays

C-Delay addresses specific administrative delays that can occur during the patent examination process. Some examples of C-Delay events include:

  • Interference proceedings.
  • Secrecy orders.
  • Successful appellate review.

3. Calculate A-Delay

To calculate A-Delay, add up all the applicant-related delays incurred during the examination process. These delays are typically measured in days. Subtract any overlapping delays to avoid double-counting. The resulting A-Delay value represents the additional days to be added to the patent term.

4. Determine B-Delay

B-Delay is calculated by identifying specific events that caused delays attributable to the USPTO. If any of these events occurred, a specific number of days will be added to the patent term. The USPTO provides guidelines and rules regarding the calculation of B-Delay, and it is essential to consult these guidelines for accurate calculations.

5. Evaluate C-Delay

C-Delay is determined by identifying any administrative delays that occurred during the examination process. These events are typically beyond the control of both the applicant and the USPTO. Each C-Delay event has a specific duration that will be added to the patent term.

6. Total the Adjustments

To obtain the final PTA, add together the A-Delay, B-Delay, and C-Delay values. This sum represents the total number of days by which the patent term will be adjusted.

7. Limitations and Additional Considerations

It is important to note that there are certain limitations and additional factors to consider when calculating PTA:

  • The total PTA cannot exceed the actual length of the patent’s term.
  • Certain types of patent applications, such as provisional applications, may not be eligible for PTA.
  • Time periods and specific events may be subject to change, so consulting the most up-to-date guidelines and regulations is essential.


Calculating patent term adjustment involves determining the start of the patent term and identifying the A-Delay, B-Delay, and C-Delay components. By accurately assessing the delays caused by the applicant, the USPTO, and administrative factors, the total PTA can be calculated. Understanding the steps and considerations involved in PTA calculation is crucial for patent owners to ensure the accurate determination of their patent’s adjusted term.

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