Also known as "stockpiling," "layering," "life-cycle management," or "line extension," evergreening generally consists of obtaining multiple patents that cover different aspects of the same product. Critics of evergreening assert that the ability to obtain multiple patents on a product, over a period of many years, effectively extends the term of exclusivity that the patent holder obtains. They further assert that this practice is abusive, impedes the introduction of generic medications, and has a negative effect upon public health in the United States. Other observers believe that the term "evergreening" is perjorative and misdescribes long-standing intellectual property policy that allows innovators to obtain patents on improvement inventions. Although the phenomenon of evergreeening may be most visible in the pharmaceutical industry, it is not necessarily limited to that industry. Continuation Application Practice

Some observers believe that the practice of patent evergreening is promoted by the availability of "continuation applications." The Hatch-Waxman Act

To the extent discussion over patent evergreening focuses upon the pharmaceutical industry, legislation commonly known as the Hatch-Waxman Act bears mention. Legislative amendments introduced in 2003 may have mitigated this effect, however. The brand-name drug company may then commence litigation against the generic firm. Other experts believe that the patent system appropriately allows for patents to issue on improvement technologies. They explain that the patent laws promote both original and improvement inventions, that most technological advance occurs incrementally, that improvements may be developed by competitors of the original innovator, that many improvement patents cover advances that are of considerable medical significance, and that patents on improvements may not impede the ability of competitors to market products that were covered by expired patents on original technologies. Observers also note that the developer of the "original" product is not always the same entity as the developer of "improvement" technologies. The ability of any innovator to obtain a patent is said to encourage competition among different firms, both in innovation and in the marketplace. Should Congress choose to address the issue of evergreening, however, a number of options exist. The USPTO recently promulgated controversial rules that would have limited the availability of continuation applications. Second, no provision of the U.S. Patent Act is specifically directed towards evergreening issues. More generalized reform of the patent system presents a third possibility for dealing with concerns over evergreening. Current bills before the 111 th Congress would potentially introduce a broad range of reforms in an effort to improve the patent system, and would perhaps respond to criticisms of evergreening practices.
"Patent evergreening" is a potentially perjorative term that generally refers to the strategy of obtaining multiple patents that cover different aspects of the same product, typically by obtaining patents on improved versions of existing products. Although the patent system allows improvement patents to be obtained in any industry, evergreening is said to be most common in the pharmaceutical industry.
Some observers believe that the availability of so-called continuation applications at the U.S. Patent and Trademark Office (USPTO) may promote evergreening practices. USPTO regulations that would have restricted the availability of continuation applications have been struck down by the courts on the grounds that the regulations exceeded the agency's statutory authority to promulgate. Others believe that the Hatch-Waxman Act, specialized legislation that governs the resolution of patent disputes between brand-name and generic drug companies, may also encourage evergreening in the pharmaceutical industry. However, 2003 amendments to the Hatch-Waxman Act may have mitigated some of these concerns.
Critics of evergreening assert that the ability to obtain multiple patents on a product, over a period of many years, effectively extends the term of exclusivity that the patent holder obtains. They further assert that this practice is abusive, impedes the introduction of generic medications, and has a negative effect upon public health in the United States.
Other observers believe that the term "evergreening" is itself inappropriate. In their view, sound intellectual property policy allows innovators to obtain patents on improvement inventions. Most technological advance occurs incrementally, they observe, and many improvement patents cover advances that are of considerable practical significance to patients and other consumers. In addition, patents on improvements may not impede the ability of competitors to market products that were covered by expired patents on original technologies. Finally, the developer of the "original" product is not always the same entity as the developer of "improvement" technologies. The ability of any innovator to obtain a patent upon an improvement invention is said to promote competition.
Should Congress conclude that the current situation is satisfactory, then no action need be taken. If Congress wishes to intervene, however, a number of options present themselves. Congress may wish to consider the regulation of continuation applications or the introduction of statutory provisions that more directly address the perceived problem of evergreening. In addition, more generalized reform of the patent system may address concerns over evergreening. Current bills before the 111th Congress would potentially introduce a broad range of reforms in an effort to improve the patent system, and would perhaps respond to criticisms of evergreening practices.