There are two important components of maintaining patent protection.   The first is routine; U.S. patent holders are required to pay maintenance fees to the U.S. government to maintain patent validity. These fees must be paid at 3.5 years, 7.5 years and 11.5 years after the patent is issued.   The second part of maintaining patent protection is to enforce your rights to stop infringement. If infringement is permitted to occur without litigation or other enforcement action to stop it, the value of a patent erodes. When requested to do so, your IP attorney can help monitor for unauthorized use of your invention. Monitoring the marketplace for illegal use of intellectual property is one of the many important responsibilities of an experienced IP attorney.