Interferences will only be conducted when at least one pending application is involved. The examination should be completed on all other issues before an interference is ever called. Interferences have been phased out by Derivation Proceedings. However, applications filed before March 16, 2013 are still eligible for interferences.

The PTO will ask questions on this chapter and often relate the topic of interferences to the topics of reexaminations, protests and appeals. However, interference proceedings are being phased out as the USPTO has switched from a first to invent to a first to file patent system.

Applications filed on or after March 16, 2013 will not be eligible for interferences. Interferences are replaced with Derivation Proceedings. You may still have questions on this Chapter as the PTO phases out the old questions and due to the fact that interferences are still possible for applications filed before March 16, 2013. It will take several years for Derivation Proceedings to come into full effect.