What is a patent term extension?

If the USPTO takes too long to start taking actions to bring your patent into being then you can get what is called a patent term extension which will protect you beyond the 20 year period that normally ensues. One reason someone would use this extension is the pharmaceutical patent often will expire shortly after getting the FDA’s approval for marketing of the drug safely. This extension allows the pharmaceutical company a longer term due to the long waiting period of the FDA’s approval before they could even start marketing the drug. Some times it can take several years to get such an approval!