How do product-by-process claims differ from method claims in patent applications?

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.

Product-by-process claims and method claims are distinct types of patent claims with different scopes and considerations:

• Product-by-process claims are directed to the product itself, defined by the process used to make it. The patentability is based on the product, not the process.
• Method claims are directed to the process or steps used to make a product or achieve a result.

According to MPEP 2113:

“The structure implied by the process steps should be considered when assessing the patentability of product-by-process claims over the prior art.”

Key differences include:

1. Focus: Product-by-process claims focus on the end product; method claims focus on the process steps.
2. Infringement: Product-by-process claims are infringed by identical products, regardless of how they’re made; method claims are infringed only when the specific steps are performed.
3. Examination: Product-by-process claims are examined based on the product structure; method claims are examined based on the specific steps and their order.

Understanding these differences is crucial for proper claim drafting and patent strategy.