How does claiming priority to a foreign application affect the patent term?

Claiming priority to a foreign application generally does not affect the term of a U.S. patent. The patent term is typically calculated from the actual U.S. filing date, not the foreign priority date.

For utility and plant patents:
– The term is 20 years from the earliest U.S. filing date of the application or any U.S. application to which it claims benefit under 35 U.S.C. 120, 121, or 365(c).
– The foreign priority date is not used in this calculation.

For design patents:
– The term is 15 years from the date of grant.
– The filing or priority dates do not affect the term.

It’s important to note that while the foreign priority date doesn’t affect the patent term, it can affect the effective filing date for prior art purposes, which can be crucial for determining patentability.

Patent Term Adjustment (PTA) may be available to extend the term of a utility or plant patent due to delays in prosecution, but this is calculated based on the actual U.S. filing date, not the foreign priority date.