USPTO Patent Prosecution Highway
The Patent Prosecution Highway (PPH) is transforming how US patent applications are fast-tracked. 

More than 30 foreign patent offices are party to PPH agreements with the USPTO. After receiving a written opinion from a partnering PPH office or an international preliminary examination report indicating allowable subject matter in a patent application, an applicant can file a request with the USPTO for fast-track examination of a related application having one or more corresponding claim.  

A request for PPH fast-track examination is usually decided by the USPTO within two months, and, if granted, the application will generally be examined within three months. The acceptance of the PPH request makes the application special and advanced out of turn for examination. Although PPH is not full faith and credit, PPH applications, on average, take significantly less time and have fewer office actions. Plus, the overall allowance rate for PPH applications is about double the overall allowance rate for non-PPH applications. 

The USPTO does not currently charge for a PPH request.